adding books

16 files changed, 5724 insertions, 0 deletions

diff --git a/Heat_And_Thermodynamics/README.txt b/Heat_And_Thermodynamics/README.txt
new file mode 100755
index 00000000..553ba2a8
--- /dev/null
+++ b/Heat_And_Thermodynamics/README.txt
@@ -0,0 +1,10 @@
+Contributed By: pratik gandhi
+Course: bca
+College/Institute/Organization: Cybercom Creation
+Department/Designation: Developer
+Book Title: Heat And Thermodynamics
+Author: A. Manna
+Publisher: Dorling Kindersley (India) Pvt. Ltd., Noida
+Year of publication: 2011
+Isbn: 9788131754009
+Edition: 1
\ No newline at end of file
diff --git a/Heat_And_Thermodynamics/ch10.ipynb b/Heat_And_Thermodynamics/ch10.ipynb
new file mode 100755
index 00000000..f0d6123b
--- /dev/null
+++ b/Heat_And_Thermodynamics/ch10.ipynb
@@ -0,0 +1,420 @@
+{
+ "metadata": {
+  "name": ""
+ },
+ "nbformat": 3,
+ "nbformat_minor": 0,
+ "worksheets": [
+  {
+   "cells": [
+    {
+     "cell_type": "heading",
+     "level": 1,
+     "metadata": {},
+     "source": [
+      "Chapter 10 : Thermodynamic relations"
+     ]
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 10.1 pageno: 329"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "# Variables\n",
+      "t = 289.6;\t\t\t#temperature in K\n",
+      "dt = 0.0244;\t\t\t#raise in temperature in deg.C\n",
+      "v1 = 0.00095;\t\t\t#volume occupied in liquid state in litres\n",
+      "v2 = 0.00079;\t\t\t#volume occupied in solid state in litres\n",
+      "\n",
+      "# Calculations\n",
+      "l = t*(v1-v2)/dt;\t\t\t#latent heat of fusion in lit.atm\n",
+      "\n",
+      "# Result\n",
+      "print 'the latent heat of fusion is %3.2f lit.atm'%(l)\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "the latent heat of fusion is 1.90 lit.atm\n"
+       ]
+      }
+     ],
+     "prompt_number": 1
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 10.2 pageno : 329"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "# Variables\n",
+      "t = 295.    \t\t\t#temperature of water in K\n",
+      "dp = 10**6.\t    \t\t#cahnge in pressure in dyne/sq.cm\n",
+      "j = 4.2*10**7;\t\t\t#joules constant in ergs/cal\n",
+      "\n",
+      "# Calculations\n",
+      "dc = -t*10**-5*dp/j;\t\t\t#change in specific heat\n",
+      "\n",
+      "# Result\n",
+      "print 'the change in specific heat is %.e cal/degree'%(dc)\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "the change in specific heat is -7e-05 cal/degree\n"
+       ]
+      }
+     ],
+     "prompt_number": 3
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 10.3 pageno: 329"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "# Variables\n",
+      "cp = 0.0909\t    \t\t#specific heat at consmath.tant pressure in cal/degree\n",
+      "t = 273;\t\t    \t#temperature in K\n",
+      "v = 0.112;\t\t\t    #specific volume in lit/deg.C\n",
+      "a = 5.01*10**(-6);\t\t#coefficient of linear expansion\n",
+      "k = 8*10**-7;\t\t\t#compressibility of copper in per atoms\n",
+      "\n",
+      "# Calculations\n",
+      "cv = cp+(9*a**2*v*t*0.024142*10**3/k);\t\t\t#specific heat at constant volume in cal/deg.C\n",
+      "\n",
+      "# Result\n",
+      "print 'specific heat at constant volume is %3.2f cal/deg.C'%(cv)\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "specific heat at constant volume is 0.30 cal/deg.C\n"
+       ]
+      }
+     ],
+     "prompt_number": 4
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 10.5 pageno : 331"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "# Variables\n",
+      "t = 289.6;\t\t\t#temperature in K\n",
+      "dt = 0.0244;\t\t\t#raise in temperature in deg.C\n",
+      "v1 = 0.00095;\t\t\t#volume occupied in liquid state in litres\n",
+      "v2 = 0.00079;\t\t\t#volume occupied in solid state in litres\n",
+      "\n",
+      "# Calculations\n",
+      "l = t*(v1-v2)/dt;\t\t\t#latent heat of fusion in lit.atm\n",
+      "\n",
+      "# Result\n",
+      "print 'the latent heat of fusion is %3.3f lit.atm'%(l)\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "the latent heat of fusion is 1.899 lit.atm\n"
+       ]
+      }
+     ],
+     "prompt_number": 5
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 10.6 pageno : 331"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "# Variables\n",
+      "l = 539;\t\t\t#latent heat of water at 100deg.C in cal\n",
+      "j = 4.2*10**7;\t\t\t#joules constant in ergs/cal\n",
+      "t = 373;\t\t\t#temperature of water in K\n",
+      "v2 = 1670;\t\t\t#volume of steam formed in cc\n",
+      "v1 = 1;\t\t\t#intial volume in cc\n",
+      "g = 981;\t\t\t#acceleration due to gravity in cm/sec**2\n",
+      "d = 13.6;\t\t\t#specific gravity of hg\n",
+      "\n",
+      "# Calculations\n",
+      "dp = l*j/(t*(v2-v1)*g*d);\t\t\t#rate of change of saturation pressure in cm of mercury\n",
+      "\n",
+      "# Result\n",
+      "print 'the rate of change of saturation pressure is %3.1f cm of hg'%(dp)\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "the rate of change of saturation pressure is 2.7 cm of hg\n"
+       ]
+      }
+     ],
+     "prompt_number": 6
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 10.7 pageno : 331"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "# Variables\n",
+      "p1 = 77.371;\t\t\t#pressure at 100.5deg.C in cm of hg\n",
+      "p2 = 74.650;\t\t\t#pressure at 99.5deg.C in cm of hg\n",
+      "g = 981;\t\t\t#universal gas constant in cm/sec**2\n",
+      "d = 13.6;\t\t\t#specific gravity\n",
+      "l = 537;\t\t\t#latent heat of vapourisation in cal/gm\n",
+      "t = 373;\t\t\t#temperature of water in K\n",
+      "j = 4.2*10**7;\t\t\t#joules constant in ergs/cal\n",
+      "v1 = 1;\t\t\t#intial volume in cc\n",
+      "\n",
+      "# Calculations\n",
+      "v2 = v1+(l*j/(t*(p1-p2)*g*d));\t\t\t#volume of gram of steam at 100deg.C in cc\n",
+      "\n",
+      "# Result\n",
+      "print 'volume of gram of steam at 100deg.C is %.f cc'%(v2)\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "volume of gram of steam at 100deg.C is 1667 cc\n"
+       ]
+      }
+     ],
+     "prompt_number": 8
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 10.8 pageno : 332"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "# Variables\n",
+      "t = 350;\t\t\t#boiling point temperature in K\n",
+      "l = 46;\t\t\t#latent heat of vapourisation in cal/gm\n",
+      "v1 = 1/1.6;\t\t\t#intial volume in cc\n",
+      "dp = 2.3;\t\t\t#change in pressure with temperature in cm of hg/deg.C\n",
+      "d = 13.6;\t\t\t#specific gravity of mercury\n",
+      "g = 981;\t\t\t#acceleration due to gravity in cm/sec**2\n",
+      "j = 4.2*10**7;\t\t\t#joukes constant in ergs/cal\n",
+      "\n",
+      "#CALCULTIONS\n",
+      "v2 = v1+(l*j)/(t*dp*d*g);\t\t\t#specific volume in cc\n",
+      "\n",
+      "# Result\n",
+      "print 'specific volume of vapour of carbon is %3.3f cc'%(v2)\n",
+      "print \"Note : Answer is slightly different because of rounding error\""
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "specific volume of vapour of carbon is 180.513 cc\n",
+        "Note : Answer is slightly different because of rounding error\n"
+       ]
+      }
+     ],
+     "prompt_number": 9
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 10.9 pageno : 332"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "# Variables\n",
+      "l = 536.;\t\t\t#latent heat of vapourisation in cal/gm\n",
+      "v1 = 1.;\t\t\t#volume of 1 gm of water in cc\n",
+      "v2 = 1600.;\t\t\t#volume of steam in cc\n",
+      "t = 373.;\t\t\t#boiling point of water in K\n",
+      "p = 1.;\t\t\t#pressure in cm of hg\n",
+      "d = 13.6;\t\t\t#specific gravity of mercury\n",
+      "g = 981.;\t\t\t#gravitational constant in cm/sec**2s/cal\n",
+      "j = 4.2*10**7;\t\t\t#joules constant in erg/cal\n",
+      "\n",
+      "# Calculations\n",
+      "dt = (t*(v2-v1)*d*g)/(l*j);\t\t\t#change in temperature in deg.C\n",
+      "\n",
+      "# Result\n",
+      "print 'change in temperature is %3.2f deg.C'%(dt)\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "change in temperature is 0.35 deg.C\n"
+       ]
+      }
+     ],
+     "prompt_number": 10
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 10.10 page no : 332"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "# Variables\n",
+      "t = 353;\t\t\t#temperature in K\n",
+      "p = 76*13.6*981;\t\t\t#pressure in dynes/sq.cm\n",
+      "v = 0.146;\t\t\t#specific volume in cc/kg\n",
+      "l = 35.6;\t\t\t#latent heat of fusion in cal/gm\n",
+      "j = 4.18*10**7;\t\t\t#joules constant in ergs/cal\n",
+      "\n",
+      "# Calculations\n",
+      "dt = t*p*v/(l*j);\t\t\t#change in melting point per atmosphere\n",
+      "\n",
+      "# Result\n",
+      "print 'the rate of change in melting point is %.3f per atmosphere'%(dt)\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "the rate of change in melting point is 0.035 per atmosphere\n"
+       ]
+      }
+     ],
+     "prompt_number": 12
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 10.11 pageno : 333"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "# Variables\n",
+      "l = 79.6*4.18*10**7;\t\t\t#latent heat of water in ergs/gm\n",
+      "t = 273.16;\t\t\t#temperature of water in K\n",
+      "v1 = 1.0001;\t\t\t#specific volume of water at 0deg.C in cc\n",
+      "v2 = 1.0908;\t\t\t#specific volume of ice at 0deg.C in cc\n",
+      "p = 1.013*10**6;\t\t\t#pressure of atmosphere in dyne/sq.cm\n",
+      "\n",
+      "# Calculations\n",
+      "dt = t*(v1-v2)*p/l;\t\t\t#change in freezing point of water in deg.C\n",
+      "\n",
+      "# Result\n",
+      "print 'change in freezing point of water is %3.4f deg.C'%(dt)\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "change in freezing point of water is -0.0075 deg.C\n"
+       ]
+      }
+     ],
+     "prompt_number": 1
+    }
+   ],
+   "metadata": {}
+  }
+ ]
+}
\ No newline at end of file
diff --git a/Heat_And_Thermodynamics/ch11.ipynb b/Heat_And_Thermodynamics/ch11.ipynb
new file mode 100755
index 00000000..083c7e47
--- /dev/null
+++ b/Heat_And_Thermodynamics/ch11.ipynb
@@ -0,0 +1,432 @@
+{
+ "metadata": {
+  "name": ""
+ },
+ "nbformat": 3,
+ "nbformat_minor": 0,
+ "worksheets": [
+  {
+   "cells": [
+    {
+     "cell_type": "heading",
+     "level": 1,
+     "metadata": {},
+     "source": [
+      "Chapter 11 : Conduction of heat"
+     ]
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 11.1 pageno : 375"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "# Variables\n",
+      "k = 0.12;\t\t\t#thermal conductivity in cgs unit\n",
+      "t1 = 200;\t\t\t#temperature at one side in deg.C\n",
+      "t2 = 50;\t\t\t#temperature at other side in deg.C\n",
+      "t = 3600;\t\t\t#time in sec\n",
+      "a = 1;\t\t\t#area in sq.cm\n",
+      "t3 = 3;\t\t\t#thickness of the plate in cm\n",
+      "\n",
+      "# Calculations\n",
+      "q = k*a*(t1-t2)*t/t3;\t\t\t#amount of heat conducted in cal\n",
+      "\n",
+      "# Result\n",
+      "print 'the amount of heat conducted is %3.2f cal'%(q)\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "the amount of heat conducted is 21600.00 cal\n"
+       ]
+      }
+     ],
+     "prompt_number": 1
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 11.2 pageno : 375"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "# Variables\n",
+      "k = 0.9;\t\t\t#thermal conductivity in cgs unit\n",
+      "a = 10;\t\t\t#area of the copper bar in sq.cm\n",
+      "t1 = 100;\t\t\t#hot side temperature in deg.C\n",
+      "t2 = 20;\t\t\t#cool side temperature in deg.C\n",
+      "d = 25;\t\t\t#thickness of the bar in cm\n",
+      "t3 = 14;\t\t\t#temperature of water when entering in deg.C\n",
+      "\n",
+      "# Calculations\n",
+      "m = k*a*(t1-t2)/(d*(t2-t3));\t\t\t#rate flow of water in gm/sec\n",
+      "\n",
+      "# Result\n",
+      "print 'rate flow of water is %3.2f gm/sec'%(m)\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "rate flow of water is 4.80 gm/sec\n"
+       ]
+      }
+     ],
+     "prompt_number": 2
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 11.3 pageno : 375"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "# Variables\n",
+      "i = 1.18;\t\t\t#current in amperes\n",
+      "e = 20;\t\t\t#potential difference across its ends in volts\n",
+      "j = 4.2;\t\t\t#joules constant in joule/cal\n",
+      "a = 2*10**4;\t\t\t#area of the slab in sq.cm\n",
+      "t = 5;\t\t\t#thickness of the plate in cm\n",
+      "t1 = 12.5;\t\t\t#temperature at hot side in K\n",
+      "t2 = 0;\t\t\t#temperature at cold side in k\n",
+      "\n",
+      "# Calculations\n",
+      "k = e*i*t/(j*a*(t1-t2));\t\t\t#thermal conductivity in cgs unit\n",
+      "\n",
+      "# Result\n",
+      "print 'thermal conductivity of slab is %3.5f cgs unit'%(k)\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "thermal conductivity of slab is 0.00011 cgs unit\n"
+       ]
+      }
+     ],
+     "prompt_number": 3
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 11.4 pageno : 375"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "import math\n",
+      "\n",
+      "# Variables\n",
+      "l = 30.;\t\t\t#length of the tube in cm\n",
+      "t = 100.;\t\t\t#temperature at outside in deg.C\n",
+      "t1 = 40.;\t\t\t#tempertaure of water when leaving tube in deg.C\n",
+      "t2 = 20.;\t\t\t#temperature of water when entering tube in deg.C\n",
+      "m = 165./60\t\t\t#mass flow rete of water in cc/sec\n",
+      "r1 = 6.;\t\t\t#internal radii in mm\n",
+      "r2 = 8.;\t\t\t#external radii in mm\n",
+      "\n",
+      "# Calculations\n",
+      "k = m*(t1-t2)*math.log(r2/r1)/(2*3.14*l*(t-((t1+t2)/2)));\t\t\t#thermal conductivity in cgs unit\n",
+      "\n",
+      "# Result\n",
+      "print 'thermal conductivity of the tube is %3.4f cgs unit'%(k)\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "thermal conductivity of the tube is 0.0012 cgs unit\n"
+       ]
+      }
+     ],
+     "prompt_number": 4
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 11.5 pageno : 376"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "# Variables\n",
+      "l1 = 1.9;\t\t\t#length of the first bar in cm\n",
+      "l2 = 5; \t\t\t#length of the second bar in cm\n",
+      "k2 = 0.92;\t\t\t#thermal conductivity in cgs unit\n",
+      "\n",
+      "# Calculations\n",
+      "k1 = k2*(l1/l2)**2;\t\t\t#thermal conductivity if first bar in cgs unit\n",
+      "\n",
+      "# Result\n",
+      "print 'thermal conductivity of first bar is %3.3f cgs unit'%(k1)\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "thermal conductivity of first bar is 0.133 cgs unit\n"
+       ]
+      }
+     ],
+     "prompt_number": 5
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 11.6 pageno : 376"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "# Variables\n",
+      "k1 = 0.92;\t\t\t#thermal conductivity of copper in cgs unit\n",
+      "k2 = 0.5;\t\t\t#thermal conductivity of alluminium in cgs unit\n",
+      "t1 = 100;\t\t\t#temperature of copper in deg.C\n",
+      "t2 = 0;\t\t\t#temperature of alluminium in deg.C\n",
+      "\n",
+      "# Calculations\n",
+      "t = k1*t1/(k1+k2);\t\t\t#welded teperature in deg.C\n",
+      "\n",
+      "# Result\n",
+      "print 'welded temperature is %3.1f deg.C'%(t)\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "welded temperature is 64.8 deg.C\n"
+       ]
+      }
+     ],
+     "prompt_number": 6
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 11.7 pageno : 376"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "# Variables\n",
+      "w = 23;\t\t\t#thermal capacity of calorimeter in cal\n",
+      "m = 440;\t\t\t#mass of water in gm\n",
+      "l = 14.6;\t\t\t#lenght of the rubber tube in cm\n",
+      "dt = 0.019;\t\t\t#rate of change in temperature in deg.C/sec\n",
+      "t = 100;\t\t\t#temperature of steam in deg.C\n",
+      "t1 = 22;\t\t\t#temperature of the water in deg.C\n",
+      "t2 = t1;\t\t\t#temperature of calorimeter in deg.C\n",
+      "r1 = 1;\t\t\t#external radii in cm\n",
+      "r2 = 0.75;\t\t\t#internal radii in cm\n",
+      "\n",
+      "# Calculations\n",
+      "k = (w+m)*dt*math.log(r1/r2)/(2*3.14*l*(t-((t1+t2)/2)));\t\t\t#thermal conductivity in cgs unit\n",
+      "\n",
+      "# Result\n",
+      "print 'thermal cnductivity of rubber tube is %3.6f cgs unit'%(k)\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "thermal cnductivity of rubber tube is 0.000354 cgs unit\n"
+       ]
+      }
+     ],
+     "prompt_number": 9
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 11.8 pageno : 377"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "# Variables\n",
+      "ti = 18;\t\t\t#inside temperature in deg.C\n",
+      "to = 4;\t\t\t#outside temperature in deg.C\n",
+      "k1 = 0.008;\t\t\t#thermal conductivity of stone in cgs unit\n",
+      "k2 = 0.12;\t\t\t#thermal conductivity of steel in cgs unit\n",
+      "t = 3600;\t\t\t#time in sec\n",
+      "t1 = 25;\t\t\t#thickness of the stone in cm\n",
+      "t2 = 2;\t\t\t#thickness of the steel in cm\n",
+      "a = 10**4;\t\t\t#area of the cottage in sq.cm\n",
+      "\n",
+      "# Calculations\n",
+      "q1 = k1*a*(ti-to)*t/(t1);\t\t\t#heat lost by stone per hour in cal\n",
+      "q2 = k2*a*(ti-to)*t/t2;\t\t\t#heat lost by steel per hour in cal\n",
+      "\n",
+      "# Result\n",
+      "print 'heat lost by stone is %3.4e cal  \\\n",
+      "\\nheat lost by steel is %.3e cal'%(q1,q2)\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "heat lost by stone is 1.6128e+05 cal  \n",
+        "heat lost by steel is 3.024e+07 cal\n"
+       ]
+      }
+     ],
+     "prompt_number": 10
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 11.9 pageno: 377"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "# Variables\n",
+      "l1 = 4;\t\t\t#length of the slab1 in cm\n",
+      "l2 = 2;\t\t\t#length of the slab2 in cm\n",
+      "k1 = 0.5;\t\t\t#thermal conductivity in cgs unit\n",
+      "k2 = 0.36;\t\t\t#thermal conductivity in cgs unit\n",
+      "t1 = 100;\t\t\t#temperature of the slab1 in deg.C\n",
+      "t2 = 0;\t\t\t#temperature of the slab2 in deg.C\n",
+      "\n",
+      "# Calculations\n",
+      "t = k1*l2*t1/((k2*l1)+(k1*l2));\t\t\t#temperature of the commaon surface in deg.C\n",
+      "\n",
+      "# Result\n",
+      "print 'the temperature of the common surface is %3.0f deg.C'%(t)\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "the temperature of the common surface is  41 deg.C\n"
+       ]
+      }
+     ],
+     "prompt_number": 11
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 11.10 pageno : 378"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "# The distance\n",
+      "\n",
+      "# Variables\n",
+      "t1 = 15.;\t\t\t#temperature of the one end of the slab in deg.C\n",
+      "t2 = 45.;\t\t\t#temperature of the other end of the slab in deg.C\n",
+      "k = 0.3;\t\t\t#thermal conductivity in cgs unit\n",
+      "d = 7.;\t\t\t#density of the material in gm/cc\n",
+      "cp = 1.;\t\t\t#specific heat of the material in kj/kg.K\n",
+      "t = 5.*3600;\t\t\t#time in sec\n",
+      "dt = 1./10;\t\t\t#thermometer reading in deg.C\n",
+      "\n",
+      "# Calculations\n",
+      "b = (3.14*d*cp/(t*k))**(0.5);\n",
+      "x = (math.log((t2-t1)/dt))/b;\t\t\t#distance from which temparature variation can be detected in cm\n",
+      "\n",
+      "# Result\n",
+      "print 'the distance from which temparature variation can be detected is %3.1f cm'%(x)\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "the distance from which temparature variation can be detected is 89.4 cm\n"
+       ]
+      }
+     ],
+     "prompt_number": 14
+    }
+   ],
+   "metadata": {}
+  }
+ ]
+}
\ No newline at end of file
diff --git a/Heat_And_Thermodynamics/ch12.ipynb b/Heat_And_Thermodynamics/ch12.ipynb
new file mode 100755
index 00000000..1281c2d6
--- /dev/null
+++ b/Heat_And_Thermodynamics/ch12.ipynb
@@ -0,0 +1,371 @@
+{
+ "metadata": {
+  "name": ""
+ },
+ "nbformat": 3,
+ "nbformat_minor": 0,
+ "worksheets": [
+  {
+   "cells": [
+    {
+     "cell_type": "heading",
+     "level": 1,
+     "metadata": {},
+     "source": [
+      "Chapter 12 : Radiation"
+     ]
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 12.1 pageno : 445"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "# Variables\n",
+      "t1 = 300;\t\t\t#temperature of the surroundings in K\n",
+      "t2 = 900;\t\t\t#temperature of the hot body p in K\n",
+      "t3 = 500;\t\t\t#temperature of the hot body q in K\n",
+      "a = 5.67*10**-8;\t\t\t#stefan boltzmann consmath.tant in W/m**2.K**4\n",
+      "\n",
+      "# Calculations\n",
+      "q1 = a*(t2**4-t1**4);\t\t\t#heat lost from hot body p in w/m**2\n",
+      "q2 = a*(t3**4-t1**4);\t\t\t#heat lost from hot body q in w/m**2\n",
+      "q = q1/q2;\t\t\t#ratio of heat lost from two subsmath.tances\n",
+      "\n",
+      "# Result\n",
+      "print 'ratio of heat lost from two substances is %3.1f/1'%(q)\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "ratio of heat lost from two substances is 11.9/1\n"
+       ]
+      }
+     ],
+     "prompt_number": 2
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 12.2 pageno : 445"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "# Variables\n",
+      "t1 = 573;\t\t\t#temperature of the hot side in K\n",
+      "t2 = 273;\t\t\t#temperature of the coll side in K\n",
+      "m = 82;\t\t\t#mass of the black body in gm\n",
+      "cp = 0.1;\t\t\t#specific heat of the black body kj/kg.K\n",
+      "dt = 0.35;\t\t\t#ice melting at a rate of temperature in deg.C/sec\n",
+      "a = 8;\t\t\t#area of black body in sq.cm\n",
+      "\n",
+      "# Calculations\n",
+      "s = m*cp*dt/(a*(t1**4-t2**4));\t\t\t#boltzmann constant in cal/sq.cm/sec/deg**4\n",
+      "\n",
+      "# Result\n",
+      "print 'boltzmann consmath.tant is %.2e cal/sq.cm/sec/deg**4'%(s)\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "boltzmann consmath.tant is 3.51e-12 cal/sq.cm/sec/deg**4\n"
+       ]
+      }
+     ],
+     "prompt_number": 4
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 12.3 pageno : 445"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "# Variables\n",
+      "r1 = 60.;\t\t\t#distance of first black body in cm\n",
+      "r2 = 30.;\t\t\t#distance of second black body in cm\n",
+      "t1 = 873.;\t\t\t#temperature of first black body in K\n",
+      "t2 = 573.;\t\t\t#temperature of the second black body in K\n",
+      "\n",
+      "# Calculations\n",
+      "i = (t2**4/t1**4)*(r1**2/r2**2);\t\t\t#ratio of intensity of radition\n",
+      "\n",
+      "# Result\n",
+      "print 'ratio of intensity of radition is %3.2f'%(i)\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "ratio of intensity of radition is 0.74\n"
+       ]
+      }
+     ],
+     "prompt_number": 5
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 12.4 pageno : 445"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "# Variables\n",
+      "t1 = 1373;\t\t\t#temperature of the sphere in K\n",
+      "t2 = 283;\t\t\t#temperature of the black body in K\n",
+      "r = 4.17*10**5;\t\t\t#rate of heat radiate in ergs/sq.cm/sec\n",
+      "a = 4*3.14*(6**2);\t\t\t#surface area of the sphere in sq.cm\n",
+      "\n",
+      "\n",
+      "tr = r*a*(t1**4/t2**4)*(2.39005736*10**(-8));\t\t\t#total heat radiated in cal/sec\n",
+      "\n",
+      "# Result\n",
+      "print 'total heat radiated is %3.1f cal/sec'%(tr)\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "total heat radiated is 2496.6 cal/sec\n"
+       ]
+      }
+     ],
+     "prompt_number": 7
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 12.5 pageno : 446"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "# Variables\n",
+      "h = 2*3.14*100;\t\t\t#heat received by the lens per min in  cal\n",
+      "m = 25.;\t\t\t#mass of the ice in gm\n",
+      "l = 80;\t\t\t#latent heat of ice in cal/gm\n",
+      "\n",
+      "# Calculations\n",
+      "t = m*l/h;\t\t\t#time for which the sun rays falls in min\n",
+      "\n",
+      "# Result\n",
+      "print 'time for which the sun rays falls is %3.3f min'%(t)\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "time for which the sun rays falls is 3.185 min\n"
+       ]
+      }
+     ],
+     "prompt_number": 8
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 12.6 page no : 446"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "# Variables\n",
+      "d = 0.35;\t\t\t#diameter of the mirror in m\n",
+      "t = 5;\t\t\t#time in min\n",
+      "T = 16;\t\t\t#temperature of water found to be in deg.C\n",
+      "m = 60;\t\t\t#mass of water in gm\n",
+      "mc = 30;\t\t\t#mass of calorimeter in gm\n",
+      "cp = 0.1;\t\t\t#specific heat of copper in cal/gm/deg.C\n",
+      "\n",
+      "# Calculations\n",
+      "q = (m+cp*mc)*T*4/(5*3.14*d**2);\t\t\t#amount of heat received by earth in cal\n",
+      "\n",
+      "# Result\n",
+      "print 'amount of heat received by earth is %3.f cal'%(q)\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "amount of heat received by earth is 2096 cal\n"
+       ]
+      }
+     ],
+     "prompt_number": 10
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 12.7 pageno : 446"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "# Variables\n",
+      "r1 = 5.;\t\t\t#radius of first sphere in cm\n",
+      "r2 = 10.;\t\t\t#radius of second sphere in cm\n",
+      "t1 = 700.;\t\t\t#temperature of the first sphere in K\n",
+      "t2 = 500.;\t\t\t#temperature of the second sphere in K\n",
+      "t = 300.;\t\t\t#temperature of the enclousure in K\n",
+      "\n",
+      "# Calculations1\n",
+      "dc = (r2/r1)*(t1**4-t**4)/(t2**4-t**4);\t\t\t#ratio of c1/c2\n",
+      "r = r1**3*dc/r2**3;\t\t\t#rate of heat loss\n",
+      "\n",
+      "# Result\n",
+      "print 'rate of loss of heat is %3.3f'%(r)\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "rate of loss of heat is 1.066\n"
+       ]
+      }
+     ],
+     "prompt_number": 16
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 12.8 pageno : 447"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "# Variables\n",
+      "t1 = 600.;\t\t\t#temperature of the black body in K\n",
+      "t0 = 300.;\t\t\t#temperature of the surroundings in K\n",
+      "d = 6.;\t\t\t#deflections in galvanometer\n",
+      "d1 = 400.;\t\t\t#deflection in divisions\n",
+      "\n",
+      "# Calculations\n",
+      "dt = (d1/d)*(t1**4-t0**4);\t\t\t#change of temperature\n",
+      "t2 = (dt+t0**4)**(1./4);\t\t\t#end temperature in K\n",
+      "\n",
+      "# Result\n",
+      "print 'end temperature of the temperature is %3.2f K'%(t2)\n",
+      "print \"Note : answer in book in incorrect. Please calculate manually.\""
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "end temperature of the temperature is 1687.45 K\n",
+        "Note : answer in book in incorrect. Please calculate manually.\n"
+       ]
+      }
+     ],
+     "prompt_number": 19
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 12.9 pageno : 447"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "# Variables\n",
+      "n = 17000;\t\t\t#luminosity of star compared to sun\n",
+      "t = 6000;\t\t\t#temperature of the sun in K\n",
+      "\n",
+      "# Calculations\n",
+      "t1 = (n*t**4)**(1./4);\t\t\t#temperature of the star in K\n",
+      "\n",
+      "# Result\n",
+      "print 'the temperature of the star is %3.f K'%(round(t1,-1))\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "the temperature of the star is 68510 K\n"
+       ]
+      }
+     ],
+     "prompt_number": 21
+    }
+   ],
+   "metadata": {}
+  }
+ ]
+}
\ No newline at end of file
diff --git a/Heat_And_Thermodynamics/ch13.ipynb b/Heat_And_Thermodynamics/ch13.ipynb
new file mode 100755
index 00000000..daac0e65
--- /dev/null
+++ b/Heat_And_Thermodynamics/ch13.ipynb
@@ -0,0 +1,176 @@
+{
+ "metadata": {
+  "name": ""
+ },
+ "nbformat": 3,
+ "nbformat_minor": 0,
+ "worksheets": [
+  {
+   "cells": [
+    {
+     "cell_type": "heading",
+     "level": 1,
+     "metadata": {},
+     "source": [
+      "Chapter 13 : Introduction to statistical thermodynamics"
+     ]
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 13.1 page no : 474"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "# Variables\n",
+      "p1 = 1./6;\t\t\t#probability for the first throw gives 6\n",
+      "p2 = 1./6;\t\t\t#probability for the first throw gives 5\n",
+      "n = 2;\t    \t\t#the no.of dice are two\n",
+      "\n",
+      "# Calculations\n",
+      "p = p1*p2*n;\t\t\t#the required probability is\n",
+      "\n",
+      "# Result\n",
+      "print 'the required probability is %3.2f'%(p)\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "the required probability is 0.06\n"
+       ]
+      }
+     ],
+     "prompt_number": 1
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 13.2 pageno : 474"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "# Variables\n",
+      "p1 = 4./52;\t\t\t#the probability for getting ace in first draw is\n",
+      "p2 = 3./51;\t\t\t#the probability for getting ace in second draw is\n",
+      "p3 = 2./50;\t\t\t#the probability for getting ace in third draw is\n",
+      "p4 = 1./49;\t\t\t#the probability for getting ace in fourth draw is\n",
+      "\n",
+      "# Calculations\n",
+      "p = p1*p2*p3*p4;\t\t\t#total probability is\n",
+      "\n",
+      "# Result\n",
+      "print 'total probability is %3.9f'%(p)\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "total probability is 0.000003694\n"
+       ]
+      }
+     ],
+     "prompt_number": 1
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 13.3 page no : 475"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "# Variables\n",
+      "n = 12.;\t\t\t#no.of particles\n",
+      "n1 = 8.;\n",
+      "n2 = 4.;\n",
+      "\n",
+      "# Calculations\n",
+      "p = n*(n-1)*(n-2)*(n-3)/(n2*(n2-1)*(n2-2)*(2**n));\t\t\t#probability of distribution (8,4)\n",
+      "\n",
+      "# Result\n",
+      "print 'probability of distribution 8(4) is %3.5f'%(p)\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "probability of distribution 8(4) is 0.12085\n"
+       ]
+      }
+     ],
+     "prompt_number": 3
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 13.4 page no: 475"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "# Variables\n",
+      "m = 32;\t\t\t#mass of the oxygen molecule in gm\n",
+      "n = 1.67*10**-27;\t\t\t#mass of one electron\n",
+      "k = 1.38*10**-23;\t\t\t#boltzzmann consmath.tant in ergs/cal\n",
+      "t = 200;\t\t\t#temperature of the oxygen in K\n",
+      "c = (100.+101)/2;\t\t\t#average speed of the oxygen molecule in m/s\n",
+      "\n",
+      "# Calculations\n",
+      "a = m*n/(2*3.14*k*t);\n",
+      "p = 4*3.14*(a**(3./2))*(c**2)*(2.303**(-a));\t\t\t#probability that the oxygen speed is lies between in m/sec\n",
+      "\n",
+      "# Result\n",
+      "print 'probability that the oxygen speed is lies between is %3.6e m/sec'%(p)\n",
+      "print \"Note : answer is slightly different because of rounding error.\""
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "probability that the oxygen speed is lies between is 6.867794e-04 m/sec\n",
+        "Note : answer is slightly different because of rounding error.\n"
+       ]
+      }
+     ],
+     "prompt_number": 10
+    }
+   ],
+   "metadata": {}
+  }
+ ]
+}
\ No newline at end of file
diff --git a/Heat_And_Thermodynamics/ch2.ipynb b/Heat_And_Thermodynamics/ch2.ipynb
new file mode 100755
index 00000000..b2e44ac0
--- /dev/null
+++ b/Heat_And_Thermodynamics/ch2.ipynb
@@ -0,0 +1,229 @@
+{
+ "metadata": {
+  "name": ""
+ },
+ "nbformat": 3,
+ "nbformat_minor": 0,
+ "worksheets": [
+  {
+   "cells": [
+    {
+     "cell_type": "heading",
+     "level": 1,
+     "metadata": {},
+     "source": [
+      "Chapter 2 : Thermometry"
+     ]
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 2.1 pageno : 29"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "# Variables\n",
+      "li = 1.23;\t\t\t#length of melting ice in mm\n",
+      "lf = 18.56;\t\t\t#length of melting ice reading in pressure of 74.24cm of mercury in mm\n",
+      "l = 10.75;\t\t\t#length of melting ice at which temperature to be calculated\n",
+      "mp = 0;\t\t\t#melting point in deg.C\n",
+      "T = 50;\t\t\t#temperature of melting ice at which length to be calculated in deg.C\n",
+      "\n",
+      "# Calculations\n",
+      "sp = 100-(76-74.24)/(2.7);\t\t\t#76cm of mercury steam point is 100 deg.C so at 74.24cm of mercury the steam point in deg.C\n",
+      "t = (l-li)*(sp-mp)/(lf-li);\t\t\t#temperature at 10.75mm of melting ice in deg.C\n",
+      "lt = ((T*(lf-li))/(sp-mp))+li;\t\t\t#length of ice at 50 deg.C\n",
+      "\n",
+      "# Result\n",
+      "print 'the temperature of melting ice at 10.75mm of hg is %3.2f deg.C \\\n",
+      " \\nthe length of ice corresponding to 50 deg.C is %3.2f mm of mercury'%(t,lt)\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "the temperature of melting ice at 10.75mm of hg is 54.58 deg.C  \n",
+        "the length of ice corresponding to 50 deg.C is 9.95 mm of mercury\n"
+       ]
+      }
+     ],
+     "prompt_number": 1
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 2.2 pageno : 30"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "# Variables\n",
+      "p1 = 23.5;\t\t\t#pressure when immersed in liquid air in cm\n",
+      "p2 = 75.;\t\t\t#pressure when immersed in ice in cm\n",
+      "p3 = 102.4;\t\t\t#pressure when immersed in steam in cm\n",
+      "T = 100.;\t\t\t#boiling point of temperature in deg.C\n",
+      "\n",
+      "# Calculations\n",
+      "t = (p1-p2)*T/(p3-p2);\t\t\t#temperature of the liquid air in deg.C\n",
+      "\n",
+      "# Result\n",
+      "print 'the temperature of liquid of air is %3.2f deg.C'%(t)\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "the temperature of liquid of air is -187.96 deg.C\n"
+       ]
+      }
+     ],
+     "prompt_number": 2
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 2.3 pageno : 30"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "# Variables\n",
+      "t1 = 283.;\t\t\t#temperature of bulb when pressure is h-2cm of hg in k\n",
+      "t2 = 546.;\t\t\t#temperature of bulb when pressure is h-22cm of hg in k\n",
+      "h1 = 2.;\t\t\t#differnce of mercury level at 283k in cm\n",
+      "h2 = 22.;\t\t\t#differnce of mercury level at 546k in cm\n",
+      "\n",
+      "# Calculations\n",
+      "h = ((h2*t1)+(h1*t2))/(t2-t1);\t\t\t#height of the barometer in cm\n",
+      "\n",
+      "# Result\n",
+      "print 'height of the barometer is %3.2f cm'%(h)\n",
+      "\n",
+      "print \"Note : Answer in book is wrong. Please calculate manually and check.\""
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "height of the barometer is 27.83 cm\n",
+        "Note : Answer in book is wrong. Please calculate manually and check.\n"
+       ]
+      }
+     ],
+     "prompt_number": 6
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "\n",
+      "Example 2.4 pageno : 30"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "# Variables\n",
+      "p0 = 76.;\t\t\t#pressure at 0 deg.C in cm of hg\n",
+      "p1 = 228.;\t\t\t#pressure (76+152) at T deg.C in cm of hg\n",
+      "t0 = 273.;\t\t\t#temperature of bulb in K\n",
+      "\n",
+      "# Calculations\n",
+      "T = p1*t0/p0;\t\t\t#temperature at 228 cm of hg pressure in K\n",
+      "\n",
+      "# Result\n",
+      "print 'the temperature of bulb is %3.2f K'%(T)\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "the temperature of bulb is 819.00 K\n"
+       ]
+      }
+     ],
+     "prompt_number": 7
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 2.5 page no : 30"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "# Variables\n",
+      "t1 = 0;\t\t\t    #temperature in deg.C\n",
+      "t2 = 100;\t\t\t#temperature in deg.C\n",
+      "t3 = 208;\t\t\t#temperature in deg.C\n",
+      "r1 = 3.5;\t\t\t#resistance in ohms\n",
+      "r2 = 5.2;\t\t\t#resistance in ohms\n",
+      "r3 = 6.9;\t\t\t#resistance in ohms\n",
+      "r4 = 9.4;\t\t\t#resistance in ohms\n",
+      "\n",
+      "# Calculations\n",
+      "tpt = (r3-r1)*100/(r2-r1);\t\t\t#temperature in deg.C\n",
+      "d = round((t3-tpt)/(2.08*1.08),2);\t\t\t#deflection\n",
+      "tp = round((r4-r1)*100/(r2-r1),2);\t\t\t#temperature in deg.C\n",
+      "t6 = (3.5*(((tp/100)**2)-tp/100))+tp;\t\t\t#temperature in deg.C\n",
+      "t7 = (3.5*(((t6/100)**2)-t6/100))+tp;\t\t\t#temperature in deg.C\n",
+      "t8 = (3.5*(((t7/100)**2)-t7/100))+tp;\t\t\t#temperature in deg.C\n",
+      "t9 = (3.5*(((t8/100)**2)-t8/100))+tp;\t\t\t#temperature in deg.C\n",
+      "\n",
+      "#Result\n",
+      "print 'the temperature of the bath is %3.2f deg.C'%(t9)\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "the temperature of the bath is 385.50 deg.C\n"
+       ]
+      }
+     ],
+     "prompt_number": 13
+    }
+   ],
+   "metadata": {}
+  }
+ ]
+}
\ No newline at end of file
diff --git a/Heat_And_Thermodynamics/ch3.ipynb b/Heat_And_Thermodynamics/ch3.ipynb
new file mode 100755
index 00000000..8becd279
--- /dev/null
+++ b/Heat_And_Thermodynamics/ch3.ipynb
@@ -0,0 +1,941 @@
+{
+ "metadata": {
+  "name": ""
+ },
+ "nbformat": 3,
+ "nbformat_minor": 0,
+ "worksheets": [
+  {
+   "cells": [
+    {
+     "cell_type": "heading",
+     "level": 1,
+     "metadata": {},
+     "source": [
+      "Chapter 3 : The mechanical equivalent of  heat"
+     ]
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 3.1 pageno : 44"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "# Variables\n",
+      "m = 20;\t\t\t#calorimeter of water equivalent in gm\n",
+      "n = 1030;\t\t\t#weight of water in gm\n",
+      "p = 2;\t\t\t#no.of paddles\n",
+      "a = 10;\t\t\t#weight of each paddle in kg\n",
+      "s = 80;\t\t\t#dismath.tance between paddles in m\n",
+      "g = 980;\t\t\t#accelaration due to gravity in cm/sec**2\n",
+      "\n",
+      "# Calculations\n",
+      "E = (p*a*1000*g*s*100);\t\t\t#potential energy in dyne cm\n",
+      "T = (E)/(1050*4.18*10**7);\t\t\t#rise in temperature in deg.C\n",
+      "\n",
+      "# Result\n",
+      "print 'the rise in temperature of water is %3.2f deg.C'%(T)\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "the rise in temperature of water is 3.57 deg.C\n"
+       ]
+      }
+     ],
+     "prompt_number": 1
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 3.2 pageno : 45"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "# Variables\n",
+      "cp = 0.1;\t\t\t#specific heat of copper in kj/kg-K\n",
+      "w = 120;\t\t\t#weight of copper calorimeter in gm\n",
+      "a = 1400;\t\t\t#weight of paraffin oil in gm\n",
+      "cp1 = 0.6;\t\t\t#specific of parafin oil in kj/kg-K\n",
+      "b = 10**8;\t\t\t#force to rotate the paddle in dynes\n",
+      "T = 16;\t\t\t#rise in temperature in deg.C\n",
+      "n = 900;\t\t\t#no.of revolutions stirred \n",
+      "pi = 3.14;\t\t\t#value of pi\n",
+      "\n",
+      "# Calculations\n",
+      "c = 2*pi*b;\t\t\t#work done by a rotating paddle per rotation in dyne cm per rotation\n",
+      "d = c*n;\t\t\t#total work done in dyne cm \n",
+      "hc = w*cp*16;\t\t\t#heat gained by calorimeter in calories\n",
+      "hp = a*cp1*16;\t\t\t#heat gaained by paraffin oil in calories \n",
+      "J = d/(hc+hp);\t\t\t#mecanical equivalent of heat in erg/cal\n",
+      "\n",
+      "# Result\n",
+      "print 'mecanical equivalent of heat is %.2e erg/cal'%(J)\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "mecanical equivalent of heat is 4.15e+07 erg/cal\n"
+       ]
+      }
+     ],
+     "prompt_number": 2
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 3.3 pageno : 45"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "# Variables \n",
+      "cp = 0.12;\t\t\t#specific heat of iron in kj/kg-K\n",
+      "m = 25;\t\t\t#mass of iron in lb\n",
+      "h = 0.4;\t\t\t#horse power developed in 3 min\n",
+      "t = 3;\t\t\t#time taken to develop the horse power in min\n",
+      "T = 17;\t\t\t#raise in temp in deg.C\n",
+      "\n",
+      "# Calculations\n",
+      "w = h*33000*t;\t\t\t#total work done in ft-lb\n",
+      "H = m*cp*T;\t\t\t#aount of heat developed in B.Th.U\n",
+      "J = (w)/H;\t\t\t#the value of mechanical equivalent of heat\n",
+      "\n",
+      "# Result\n",
+      "print 'the mechanical equivalent of water is %3.1f ft-lb/B.Th.U'%(J)\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "the mechanical equivalent of water is 776.5 ft-lb/B.Th.U\n"
+       ]
+      }
+     ],
+     "prompt_number": 3
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 3.4 pageno : 45"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "# Variables \n",
+      "n = 2.;\t\t\t#no.of lead blocks\n",
+      "m = 210.;\t\t\t#mass of each lead block in gm\n",
+      "v = 20000.;\t\t\t#velocity of block relative to earth in cm/sec\n",
+      "J = 4.2*10**7;\t\t\t#mechanical equivalent of heat in ergs/calorie\n",
+      "cp = 0.03;\t\t\t#specific heat of lead in kj/kg-K\n",
+      "\n",
+      "# Calculations\n",
+      "E = (m*v**2)/2;\t\t\t#kinetic energy of each block in ergs\n",
+      "E2 = n*E;\t\t\t#total kinetic energy in ergs\n",
+      "T = E2/(J*m*n*cp);\t\t\t#mean rise in temperature in T\n",
+      "\n",
+      "# Result\n",
+      "print 'the mean rise in temperature is %3.1f deg.C'%(T)\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "the mean rise in temperature is 158.7 deg.C\n"
+       ]
+      }
+     ],
+     "prompt_number": 4
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 3.5 pageno : 45"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "# Variables \n",
+      "h = 150;\t\t\t#height froom which ball fallen in ft\n",
+      "cp = 0.03;\t\t\t#specific heat of lead in kj/kg-K\n",
+      "J = 778;\t\t\t#mechanical equivalent of heat in ft lb/B.Th.U\n",
+      "\n",
+      "# Calculations\n",
+      "#work done in falling is equal to heat absorbed by the ball\n",
+      "T = 160./(J*cp)*(5./9);\t\t\t#the raise in temperature in T\n",
+      "\n",
+      "# Result\n",
+      "print 'the raise in temperature is %3.1f deg.C'%(T)\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "the raise in temperature is 3.8 deg.C\n"
+       ]
+      }
+     ],
+     "prompt_number": 5
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 3.6 pageno : 46"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "import math \n",
+      "# Variables \n",
+      "w = 26.6;\t\t\t#work done one horse in to raise the temperature in lb\n",
+      "T1 = 32.;\t\t\t#temperature at initial in deg.F\n",
+      "T2 = 212.;\t\t\t#temperature at final in deg.F\n",
+      "t = 2.5;\t\t\t#time to raise the tmperature in hrs\n",
+      "p = 25.;\t\t\t#percentage of heat lossed \n",
+      "\n",
+      "# Calculations\n",
+      "#only 75% of heat is utillised\n",
+      "x = w*180.*100.*778./((100-p)*150);\t\t\t#the rate at which horse worked\n",
+      "\n",
+      "# Result\n",
+      "print 'the rate at which horse worked is %3.0f ft-lb wt/min'%(x)\n",
+      "print \"Note : Answer in book is rounded off, Please calculate manually. This answer is accurate.\""
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "the rate at which horse worked is 33112 ft-lb wt/min\n",
+        "Note : Answer in book is rounded off, Please calculate manually. This answer is accurate.\n"
+       ]
+      }
+     ],
+     "prompt_number": 7
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 3.7 pageno : 46"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "# Variables \n",
+      "l = 100.;\t\t\t#length of glass tube in cm\n",
+      "m = 500.;\t\t\t#mass of mercury in glass tube in gm\n",
+      "n = 20.;\t\t\t#number of times inverted i succession\n",
+      "cp = 0.03;\t\t\t#specific heat of mercury in cal/gm/deg.C\n",
+      "J = 4.2;\t\t\t#joule's equivalent in j/cal\n",
+      "g = 981.;\t\t\t#accelaration due to gravity in cm/s**2\n",
+      "\n",
+      "# Calculations\n",
+      "PE = m*g*l;\t\t\t#potential energy for each time in ergs\n",
+      "TE = PE*n;\t\t\t#total loss in ergs\n",
+      "T = TE/(m*cp*J*10**7);\t\t\t#rise in temperature in deg.C\n",
+      "#if T is the rise in temperature,then heat devoloped is m*cp*T\n",
+      "\n",
+      "# Result\n",
+      "print 'the rise in temperature is %3.2f deg.C'%(T)\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "the rise in temperature is 1.56 deg.C\n"
+       ]
+      }
+     ],
+     "prompt_number": 8
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 3.8 page no : 46"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "\n",
+      "# Variables \n",
+      "d = 0.02;\t\t\t#diameter of the copper wire in cm\n",
+      "i = 1;\t\t\t#current in amp\n",
+      "T = 100;\t\t\t#maximum steady temperature in deg.C\n",
+      "r = 2.1;\t\t\t#resistance of the wire in ohm cm\n",
+      "J = 4.2;\t\t\t#mechanical equivalent of heat in j/cal\n",
+      "a = 3.14*d**2/4;\t\t\t#area of the copper wire in sq.cm\n",
+      "a2 = 1;\t\t\t#area of the copper surface in sq.cm\n",
+      "\n",
+      "# Calculations \n",
+      "l = 1/(2*3.14*d/2);\t\t\t#length corresponding to the area in cm\n",
+      "R = r*l/a;\t\t\t#resistance of the copper wire in ohm\n",
+      "w = R*a2**2;\t\t\t#work done in joule\n",
+      "h = w/J;\t\t\t#heat devoleped in cal\n",
+      "\n",
+      "# Result\n",
+      "print 'the heat developed is %.f calories'%(round(h,-1))\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "the heat developed is 25360 calories\n"
+       ]
+      }
+     ],
+     "prompt_number": 11
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 3.9 pageno: 47"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "import math \n",
+      "\n",
+      "# Variables\n",
+      "h = 10000;\t\t\t#vertical height of water fall in cm\n",
+      "v = 5;\t\t\t    #volume disharged per sec in litres\n",
+      "J = 4.18;\t\t\t#joule's constant in j/cal\n",
+      "g = 981;\t\t\t#accelaration due to gravity in cm/sec**2\n",
+      "\n",
+      "# Calculations\n",
+      "m = v*1000;\t\t\t#mass of water disharged per sec in gm\n",
+      "w = m*h*g;\t\t\t#work done in falling through 100m in erg\n",
+      "H = (v*10**7 *g)/(J*10**7);\t#quantity of heat produced in cal\n",
+      "T = H/m;\t\t\t#rise in temperature in deg.C\n",
+      "\n",
+      "# Result\n",
+      "print 'the quantity of heat produced is %3f cal  \\\n",
+      "\\nthe rise in temperature is %3.2f deg.C'%(H,T)\n",
+      "\n",
+      "print \"Note : Answer for part A in book is wrong. Please calculate manually.\""
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "the quantity of heat produced is 1173.444976 cal  \n",
+        "the rise in temperature is 0.23 deg.C\n",
+        "Note : Answer for part A in book is wrong. Please calculate manually.\n"
+       ]
+      }
+     ],
+     "prompt_number": 15
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 3.10 page no : 47"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "\n",
+      "# Variables \n",
+      "cp = 0.03;\t\t\t#specific heat of lead in kj/kg.k\n",
+      "v = 10000;\t\t\t#initial velocity of bullet in cm/sec\n",
+      "J = 4.2*10**7;\t\t\t#joules constant in ergs/cal\n",
+      "\n",
+      "# Calculations\n",
+      "ke = (v**2)/2;\t\t\t#kinetic energy of the bullet per unit mass in (cm/sec)**2\n",
+      "T = ke*95/(cp*J*100);\t\t\t#rise in temperature in deg.C\n",
+      "\n",
+      "# Result\n",
+      "print 'the rise in temperature is %3.1f deg.C'%(T)\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "the rise in temperature is 37.7 deg.C\n"
+       ]
+      }
+     ],
+     "prompt_number": 16
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 3.11 page no : 47"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "# Variables \n",
+      "h = 5000.;\t\t\t#height of the niagara falls in cm\n",
+      "J = 4.2*10**7;\t\t#joules constant in ergs per cal\n",
+      "g = 981;\t\t\t#accelaration due to gravity in cm/sec**2\n",
+      "\n",
+      "#CALCULATIONS\n",
+      "w = h*g;\t\t\t#work done per unit mass in ergs/gn\n",
+      "T = w/J;\t\t\t#rise in temperature in deg.C\n",
+      "\n",
+      "# Result\n",
+      "print 'the rise in temperature is %3.2f deg.C'%(T)\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "the rise in temperature is 0.12 deg.C\n"
+       ]
+      }
+     ],
+     "prompt_number": 17
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 3.12 page no : 48\n"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "import math \n",
+      "\n",
+      "# Variables \n",
+      "E1 = 3.75;\t\t\t#potential difference in v\n",
+      "E2 = 3.;\t\t\t#potential differnce in v\n",
+      "i1 = 2.5;\t\t\t#current in amp\n",
+      "i2 = 2;\t\t\t    #current in amp\n",
+      "T = 2.7;\t\t\t#the rise in temperature of the water in deg.C\n",
+      "m1 = 48.;\t\t\t#water flow rate at 3 volts in gm/min\n",
+      "m2 = 30.;\t\t\t#water flow rate at 3.75volts in gm/min\n",
+      "s = 1;\t\t\t    #specific heat of the water kj/kg-K\n",
+      "\n",
+      "# Calculations\n",
+      "J = (E1*i1-E2*i2)/(s*T*(m1-m2)/60);\t\t\t#the mechanical equivalent in j/cal\n",
+      "\n",
+      "# Result\n",
+      "print 'the mechanical equivalent is %3.3f j/cal'%(J)\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "the mechanical equivalent is 4.167 j/cal\n"
+       ]
+      }
+     ],
+     "prompt_number": 18
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 3.13 page no : 48"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "\n",
+      "# Variables \n",
+      "R = 64*10**7;\t\t\t#mean radius of the earth in cm\n",
+      "cp = 0.15;\t\t\t#specific heat of earth in kj/kg-K\n",
+      "J = 4.2*10**7;\t\t\t#joules consmath.tant in erg/cal\n",
+      "\n",
+      "# Calculations\n",
+      "i = 2./5*R**2;\t\t\t#moment of inertia of the earth per unit mass in joules\n",
+      "w = (2*3.14)/(24*60*60);\t\t\t#angular velocity of the earth in rad/sec\n",
+      "T = (i*w**2)/(2*J*cp);\t\t\t#rise in temperature in deg.C\n",
+      "\n",
+      "# Result\n",
+      "print 'the rise in the temperature is %.1f deg C'%(T)\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "the rise in the temperature is 68.7 deg C\n"
+       ]
+      }
+     ],
+     "prompt_number": 6
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 3.14 page no : 49"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "# Variables \n",
+      "cp = 1.25;\t\t\t#specific heat of helium inkj/kg-K\n",
+      "v = 1000;\t\t\t#volume of the gas in ml\n",
+      "w = 0.1785;\t\t\t#mass of the gas at N.T.P in gm\n",
+      "p = 76*13.6*981;\t#pressure of the gas at N.T.P in dynes\n",
+      "T = 273;\t\t\t#temperature at N.T.P in K\n",
+      "\n",
+      "# Calculations\n",
+      "V = 1000/w;\t\t\t#volume occupied by the 1gm of helium gas in cc\n",
+      "cv = cp/1.66;\t\t#specific heat at constant volume it is monatomuc gas kj/kg-K\n",
+      "r = p*V/T;\t\t\t#gas constant in cm**3.atm./K.mol\n",
+      "J = r/(cp-cv);\t\t#mechanical equivalent of heat in erg/cal\n",
+      "\n",
+      "# Result\n",
+      "print 'the mechanical equivalent of heat is %.2e ergs/calories'%(J)\n",
+      "print \"Note: answer slightly different because of rounding error.\""
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "the mechanical equivalent of heat is 4.19e+07 ergs/calories\n",
+        "Note: answer slightly different because of rounding error.\n"
+       ]
+      }
+     ],
+     "prompt_number": 20
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "\n",
+      "Example 3.15 pageno : 49"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "# Variables \n",
+      "n = 1./273;     \t\t\t#coefficent of expaaansion of air\n",
+      "a = 0.001293;\t    \t\t#density of air in gm/cc\n",
+      "cp = 0.2389;\t\t    \t#specific heat at consmath.tant pressure in kj/kg.K\n",
+      "p = 76*13.6*981;\t\t\t#pressure at 0 deg.C in dynes\n",
+      "\n",
+      "# Calculations\n",
+      "J = (p*n)/(a*(cp-(cp/1.405)));\t\t\t#mechanical equivalent of heat\n",
+      "\n",
+      "# Result\n",
+      "print 'mechanical equivalent of heat is %.2e ergs/cal'%(J)\n",
+      "print \"Note: answer slightly different because of rounding error.\"\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "mechanical equivalent of heat is 4.17e+07 ergs/cal\n",
+        "Note: answer slightly different because of rounding error.\n"
+       ]
+      }
+     ],
+     "prompt_number": 22
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 3.16 pageno : 49"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "import math \n",
+      "# Variables \n",
+      "r = 120./60;\t\t\t#rate of flow of water in gm/sec\n",
+      "T1 = 27.30;\t\t\t#temperature at initial in deg.C\n",
+      "T2 = 33.75;\t\t\t#temperature at final in deg.C\n",
+      "v = 12.64;\t\t\t#potential drop in volts\n",
+      "s = 1.; \t\t\t#specific heat of water in kj/kg-K\n",
+      "i = 4.35;\t\t\t#current through the heating element in amp\n",
+      "\n",
+      "# Calculations\n",
+      "J = (v*i)/(r*s*(T2-T1));\t\t\t#the mechanical equivalent of heat in joule/calorie\n",
+      "\n",
+      "# Result\n",
+      "print 'the mechanical equivalent of heat is %3.2f j/cal'%(J)\n",
+      "print \"Note: answer slightly different because of rounding error.\""
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "the mechanical equivalent of heat is 4.26 j/cal\n",
+        "Note: answer slightly different because of rounding error.\n"
+       ]
+      }
+     ],
+     "prompt_number": 24
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 3.17 page no : 50"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "\n",
+      "# Variables \n",
+      "cp = 6.865;\t\t\t#molar specific heat of hydrogen at consmath.tant pressure in kj/kg-K\n",
+      "cv = 4.880;\t\t\t#molar specific heat of hydrogen at consmath.tant volume in kj/kg-K\n",
+      "p = 1.013*10**6;\t\t\t#atmospheric pressure in dynes/cm**2\n",
+      "v = 22.4*10**3;\t\t\t#gram molar volume in ml\n",
+      "T = 273;\t\t\t#temperature at N.T.P in kelvins\n",
+      "\n",
+      "# Calculations\n",
+      "J = (p*v)/(T*(cp-cv));\t\t\t#mechanical equivalent of heat\n",
+      "\n",
+      "# Result\n",
+      "print 'the mechanical equivalent of heat is %.2e ergs/cal'%(J)\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "the mechanical equivalent of heat is 4.19e+07 ergs/cal\n"
+       ]
+      }
+     ],
+     "prompt_number": 26
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 3.18 page no : 50"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "import math \n",
+      "# Variables\n",
+      "v = 1000.;\t\t\t#volume of hydrogen in ml\n",
+      "t = 273.;\t\t\t#tempature of hydrogen in kelvin\n",
+      "p = 76.;\t\t\t#pressure of hydrogen in mm of hg\n",
+      "w = 0.0896;\t\t\t#weigh of hydrogen in gm\n",
+      "cp = 3.409;\t\t\t#specific heat of hydogen in kj/kg-K\n",
+      "cv = 2.411;\t\t\t#specific heat of hydrogen in kj/kg-K\n",
+      "g = 981.;\t\t\t#accelaration due to gravity in cm/sec**2\n",
+      "a = 13.6;\t\t\t#density of mercury in gm/cm**2\n",
+      "\n",
+      "# Calculations\n",
+      "J = (p*v*g*a)/(w*t*(cp-cv));\t\t\t#mechanical equivalent of heat in ergs/cals\n",
+      "\n",
+      "# Result\n",
+      "print 'mechanical equivalent of heat is %.2e ergs/calorie'%(J)\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "mechanical equivalent of heat is 4.15e+07 ergs/calorie\n"
+       ]
+      }
+     ],
+     "prompt_number": 1
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 3.19 page no : 50"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "# Variables\n",
+      "cp = 0.23;\t\t\t#specific heat at constant pressure in kj/kg-K\n",
+      "a = 1.18;\t\t\t#density of air in gm/lit\n",
+      "J = 4.2*10**7;\t\t\t#mechanical equivalent of heat in ergs/cal\n",
+      "t = 300;\t\t\t#temperature of air in kelvin\n",
+      "p = 73*13.6*981;\t\t\t#pressure of air in dynes\n",
+      "\t\t\t#cp-cv = (r/J) = pv/(tj)\n",
+      "\n",
+      "#CALCULATON\n",
+      "cv = cp-(p*1000/(a*t*J));\t\t\t#specific heat at constant volume in calories\n",
+      "\n",
+      "# Result\n",
+      "print 'the specific heat at constant volume is %.4f calories'%(cv)\n",
+      "print \"Note: answer slightly different because of rounding error.\""
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "the specific heat at constant volume is 0.1645 calories\n",
+        "Note: answer slightly different because of rounding error.\n"
+       ]
+      }
+     ],
+     "prompt_number": 29
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 3.20 pageno : 51"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "# Variables\n",
+      "t1 = 0;\t\t\t#temperature of water in deg.C\n",
+      "t2 = 0;\t\t\t#temperature of ice in deg.C\n",
+      "J = 4.18*10**7;\t\t\t#the joules thomson coefficent in erg/cal\n",
+      "l = 80;\t\t\t#latent heat og fusion kj/kg\n",
+      "g = 981;\t\t\t#accelaration due to gravity in cm/sec**2\n",
+      " \n",
+      "# Calculations\n",
+      "h = l*J/(15*g);\t\t\t#height from which ice has fallen\n",
+      "\n",
+      "# Result\n",
+      "print 'the height from which ice has fallen is %.2e cm'%(h)\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "the height from which ice has fallen is 2.27e+05 cm\n"
+       ]
+      }
+     ],
+     "prompt_number": 30
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 3.21 page no : 51"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "\n",
+      "# Variables\n",
+      "T = 80;\t\t\t#temperature of bullet in deg.C\n",
+      "cp = 0.03;\t\t\t#specific heat of lead in kj/kg-K\n",
+      "J = 4.2;\t\t\t#mechanical equivalent of heat in j/cal\n",
+      "\n",
+      "# Calculations\n",
+      "h = T*cp;\t\t\t#heat developed per unit mass in calorie\n",
+      "v = (J*10**7*h*2/0.9)**0.5;\t\t\t#velocity of bullet in cm/sec\n",
+      "\n",
+      "# Result\n",
+      "print 'the velocity of bullet is %.1e cm/sec'%(v)\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "the velocity of bullet is 1.5e+04 cm/sec\n"
+       ]
+      }
+     ],
+     "prompt_number": 31
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 3.22 pageno : 51"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "# Variables\n",
+      "w = 5.0;\t\t\t#weight of lead ball in lb\n",
+      "cp = 0.032;\t\t\t#specific heat of lead in Btu/lbdeg.F\n",
+      "h = 50;\t\t\t#height at which ball thrown in feets\n",
+      "v = 20;\t\t\t#vertical speed in ft/sec\n",
+      "g = 32;\t\t\t#accelararion due to gravity in ft/sec**2\n",
+      "\n",
+      "# Calculations\n",
+      "u = (v**2)+2*g*h\n",
+      "ke = (w/2*(u));\t\t\t#kinetic energy of the ball at ground\n",
+      "T = ke/(2*32*778*w*cp);\t\t\t#rise of temperature in deg.F\n",
+      "\n",
+      "# Result\n",
+      "print 'the rise in temperature is %.1f deg.F'%(T)\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "the rise in temperature is 1.1 deg.F\n"
+       ]
+      }
+     ],
+     "prompt_number": 32
+    }
+   ],
+   "metadata": {}
+  }
+ ]
+}
\ No newline at end of file
diff --git a/Heat_And_Thermodynamics/ch4.ipynb b/Heat_And_Thermodynamics/ch4.ipynb
new file mode 100755
index 00000000..6682bd50
--- /dev/null
+++ b/Heat_And_Thermodynamics/ch4.ipynb
@@ -0,0 +1,1097 @@
+{
+ "metadata": {
+  "name": ""
+ },
+ "nbformat": 3,
+ "nbformat_minor": 0,
+ "worksheets": [
+  {
+   "cells": [
+    {
+     "cell_type": "heading",
+     "level": 1,
+     "metadata": {},
+     "source": [
+      "Chapter 4 : Kinetic theory of gases"
+     ]
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 4.1 page no : 137\n"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "# Variables\n",
+      "t = 273;\t\t\t    #temperture of the oxygen molecule in K\n",
+      "m = 32;\t\t        \t#molecular mass of the gas in gm\n",
+      "r = 8.32*10**7;\t\t\t#molar gas consmath.tant in ergs per mole\n",
+      "v2 = 33200.;\t\t\t#velocity of the gas in cm/sec\n",
+      "\n",
+      "# Calculations\n",
+      "v1 = ((3*r*t)/m)**(1./2);\t\t\t#rms velocity of the molecule in cm/s\n",
+      "T = ((v2*v2*m)/(3*r));\t\t\t#temperature of the molecule with sound has velocity in K\n",
+      "\n",
+      "# Result\n",
+      "print 'the rms velocity of the molecule is %.2e cm/s  \\\n",
+      "\\nthe temperature of the molecule is %3.0f K'%(v1,T)\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "the rms velocity of the molecule is 4.61e+04 cm/s  \n",
+        "the temperature of the molecule is 141 K\n"
+       ]
+      }
+     ],
+     "prompt_number": 1
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 4.2 page no : 137"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "\n",
+      "# Variables\n",
+      "t1 = 308.;\t\t\t#temperature of the nitrogen molecule in K\n",
+      "m1 = 28.;\t\t\t#molecular mass of the nitrogen in gm\n",
+      "m2 = 2.;\t\t\t#molecular mass of the hydrogen molecule in gm\n",
+      "\n",
+      "# Calculations\n",
+      "t2 = (t1*m2/m1);\t\t\t#temperature of the hydrogen molecule in K\n",
+      "\n",
+      "# Result\n",
+      "print 'the temperature of the hydrogen molecule is %3.0fK'%(t2)\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "the temperature of the hydrogen molecule is  22K\n"
+       ]
+      }
+     ],
+     "prompt_number": 2
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 4.3 pageno : 138"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "# Variables\n",
+      "y = 0.00129;\t\t\t#density of the air in gm/cc\n",
+      "p = 76;\t\t\t#pressure of the nitrogen molecule in cm\n",
+      "g = 981;\t\t\t#accelaration due to gravity in cm/sec**2\n",
+      "m = 13.6;\t\t\t#density of the mercury in gm/cc\n",
+      "\n",
+      "# Calculations\n",
+      "v = ((3*p*g*m)/y)**(1./2);\t\t\t#rms velocity of air at ntp in cm/sec\n",
+      "\n",
+      "# Result\n",
+      "print 'the rms velocity of the air is %.2e cm/sec'%(v)\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "the rms velocity of the air is 4.86e+04 cm/sec\n"
+       ]
+      }
+     ],
+     "prompt_number": 3
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 4.4 pageno : 138"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "# Variables\n",
+      "d = 16*0.000089;\t\t\t#density of the oxygen molecule in gm/cc\n",
+      "p = 76;\t\t\t#pressure of the air in cm\n",
+      "g = 981;\t\t\t#gravitaitonal accelaration in cm/sec**2\n",
+      "m = 13.6;\t\t\t#density of the mercury in gm/cc\n",
+      "\n",
+      "# Calculations\n",
+      "v = ((3*p*g*m)/d)**(1./2);\t\t\t#velocuty of the oxygen molecule in cm/sec\n",
+      "\n",
+      "# Result\n",
+      "print 'velocity of oxygen molecule is %.2e cm/sec'%(v)\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "velocity of oxygen molecule is 4.62e+04 cm/sec\n"
+       ]
+      }
+     ],
+     "prompt_number": 5
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 4.5 pageno : 138"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "# Variables\n",
+      "t = 273;\t\t\t#temperature of the hydrogen molecule in K\n",
+      "n = 6.03*10**23;\t\t\t#1 mole of hydrogen molecules\n",
+      "r = 8.31*10**7;\t\t\t#universal gas consmath.tant in erg/K/mole\n",
+      "\n",
+      "# Calculations\n",
+      "e = (1.5*r*t)/n;\t\t\t#kinetic energy of the hydrogen molecule in erg\n",
+      "\n",
+      "# Result\n",
+      "print \"the kinetic energy of the hydrogen molecule is %.2e erg\"%e\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "the kinetic energy of the hydrogen molecule is 5.64e-14 erg\n"
+       ]
+      }
+     ],
+     "prompt_number": 7
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 4.6 page no : 138"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "# Variables\n",
+      "m = 1.;\t\t\t#mass of the oxygen in gm\n",
+      "r = 8.31*10**7;\t\t\t#universal gas consmath.tant in erg/K/mole\n",
+      "t = 320.;\t\t\t#temperature of the oxygen in K\n",
+      "\t\t\t#for 1gm mole k.e is 1.5rt then for 1 gm oxygen (1/32)(k.e)\n",
+      "\n",
+      "# Calculations\n",
+      "e = (m/32)*(3*r*t/2);\t\t\t#kinetic energy of the oxygen in erg\n",
+      "\n",
+      "# Result\n",
+      "print 'the kinetic energy of the oxygen is %.2e erg'%(e)\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "the kinetic energy of the oxygen is 1.25e+09 erg\n"
+       ]
+      }
+     ],
+     "prompt_number": 9
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 4.7 pageno : 138"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "# Variables\n",
+      "t = 273;\t\t\t#temperature at ntp in K\n",
+      "\t\t\t#rms velocity of oxygen is 3/2 times its rms velocity at ntp then e1 = (3/2)*e\n",
+      "\n",
+      "# Calculations\n",
+      "t1 = (9.*t/4.);\t\t\t#temperature of the oxygen molecule in K\n",
+      "\n",
+      "# Result\n",
+      "print 'temperature of the oxygen in %3.1f K'%(t1)\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "temperature of the oxygen in 614.2 K\n"
+       ]
+      }
+     ],
+     "prompt_number": 11
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 4.8 page no : 139"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "# Variables\n",
+      "p = 10;\t\t\t#pressure of the gas in atm\n",
+      "v = 5000;\t\t\t#volume of the gas in ml\n",
+      "l = 76;\t\t\t#length of the mercury in barometer in cm\n",
+      "g = 981;\t\t\t#accelaration due to gravity in cm/sec**2\n",
+      "d = 13.6;\t\t\t#density of the mercury in gm/cc\n",
+      "\n",
+      "# Calculations\n",
+      "e = 3*p*v*l*g*d;\t\t\t#kinetic energy of the molecule in ergs\n",
+      "\n",
+      "# Result\n",
+      "print 'the kinetic energy of the molecule is %.2e ergs'%(e)\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "the kinetic energy of the molecule is 1.52e+11 ergs\n"
+       ]
+      }
+     ],
+     "prompt_number": 12
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 4.9 page no : 139"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "# Variables\n",
+      "t = 323;\t\t\t#temperature of the hydrogen molecule in K\n",
+      "m1 = 1;\t\t\t#mass of the hydrogen molecule in gm\n",
+      "m2 = 2;\t\t\t#molecular weight of the hydrogen in gm\n",
+      "r = 8.3*10**7;\t\t\t#universal gas consmath.tant in erg/K/mole\n",
+      "\n",
+      "# Calculations\n",
+      "e = (m1*r*t*3/(m2*2));\t\t\t#kinetic enrgy of the hydrogen molecule in ergs\n",
+      "\n",
+      "# Result\n",
+      "print 'the kinetic energy of the molecule is %.0e ergs'%(e)\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "the kinetic energy of the molecule is 2e+10 ergs\n"
+       ]
+      }
+     ],
+     "prompt_number": 13
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 4.10 page no : 139"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "\n",
+      "# Variables\n",
+      "t1 = 273;\t\t\t#temperature of the hydrogen molecule at n.t.p in K\n",
+      "\n",
+      "# Calculations\n",
+      "#rms value of hydrogen molecule is double to its rms value at n.t.p, so 3rt/m = 4(3rt/m)\n",
+      "t2 = 4*t1;\t\t\t#temperature of the hydrogen molecule in K\n",
+      "\n",
+      "# Result\n",
+      "print 'the temperature of the hydrogen molecule is %.f K'%(t2)\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "the temperature of the hydrogen molecule is 1092 K\n"
+       ]
+      }
+     ],
+     "prompt_number": 14
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 4.11 page no : 139"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "# Variables\n",
+      "t1 = 273.;\t\t\t#temperature of the hydrogen molecule in K\n",
+      "t2 = 373;\t\t\t#temperature of the hydrogen molecule in K\n",
+      "d = 0.0000896;\t\t\t#density of the hydrogen molecule in gm/cc\n",
+      "p = 76*13.6*981;\t\t\t#pressure of the hydrogen molecule in gm/cm/sec**2\n",
+      "\n",
+      "# Calculations\n",
+      "v0 = (3*p/d)**(0.5);\t\t\t#rms velocity at 0deg.C\n",
+      "v100 = v0*(t2/t1)**(0.5);\t\t\t#rms velocity at 100deg.C\n",
+      "\n",
+      "# Result\n",
+      "print 'the rms velocity at 0deg.C is %.2e cm/sec  \\\n",
+      "\\nthe rms velocity at 100deg.C is %.3e cm/sec'%(v0,v100)\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "the rms velocity at 0deg.C is 1.84e+05 cm/sec  \n",
+        "the rms velocity at 100deg.C is 2.154e+05 cm/sec\n"
+       ]
+      }
+     ],
+     "prompt_number": 16
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 4.12 page no : 140"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "\n",
+      "# Variables\n",
+      "cp = 6.84;\t\t\t#specific heat at consmath.tant pressure in cal/gm mole/deg.C\n",
+      "r = 8.31*10**7;\t\t\t#universal gas constant in ergs/gm mole/deg.C\n",
+      "v = 130000;\t\t\t#velocity of sound in cm/sec\n",
+      "j = 4.2*10**7;\t\t\t#joules constant in ergs/cal\n",
+      "\n",
+      "#CALCULATION\n",
+      "cv = cp-(r/j);\t\t\t#specific heat at constant volume in gm-mole/deg.C\n",
+      "y = (cp/cv);\t\t\t#index of co-efficient\n",
+      "v1 = (3/y)**(0.5)*v;\t\t\t#rms velocity in cm/sec\n",
+      "\n",
+      "# Result\n",
+      "print 'the rms velocity of gas molecule is %.3e cm/sec'%(v1)\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "the rms velocity of gas molecule is 1.898e+05 cm/sec\n"
+       ]
+      }
+     ],
+     "prompt_number": 17
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 4.13 page no : 140"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "# Variables\n",
+      "t = 300;\t\t\t#temperature of the oxygen molecule in K\n",
+      "n = 6.02*10**23;\t\t\t#avagdrao's number\n",
+      "m = 32/n;\t\t\t#mass of each molecule in oxygen\n",
+      "k = 1.38*10**(-16);\t\t\t#boltzmann consmath.tant in erg/deg\n",
+      "\n",
+      "# Calculations\n",
+      "v = (8*k*t/(3.14*m))**(0.5);\t\t\t#average velocity of oxygen molecule in cm/sec\n",
+      "v2 = v*0.022384;\t\t\t#velocity in miles/hrs\n",
+      "\n",
+      "# Results\n",
+      "print 'the avg velocity of  oxygen molecule is %.f miles/hour'%(v2)\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "the avg velocity of  oxygen molecule is 997 miles/hour\n"
+       ]
+      }
+     ],
+     "prompt_number": 18
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 4.14 page no : 140"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "# Variables\n",
+      "v1 = 2.4;\t\t\t#velocity of first particle in km/sec\n",
+      "v2 = 2.6;\t\t\t#velocity of second particle in km/sec\n",
+      "v3 = 3.7;\t\t\t#velocity of third particle in km/sec\n",
+      "\n",
+      "# Calculations\n",
+      "rv = ((v1**2+v2**2+v3**2)/(3))**(0.5);\t\t\t#rms velocity of the particles in km/sec\n",
+      "mv = (v1+v2+v3)/(3);\t\t\t                #mean velocity of the particles in km/sec\n",
+      "r = rv/mv;\t\t\t                            #ratio of the rms to mean velocity\n",
+      "\n",
+      "# Results\n",
+      "print 'the ratio of rms to mean velocity is %3.3f'%(r)\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "the ratio of rms to mean velocity is 1.019\n"
+       ]
+      }
+     ],
+     "prompt_number": 19
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 4.15 pageno : 141"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "# Variables\n",
+      "n = 2.76*10**19;\t\t\t#no.of molecules per cc\n",
+      "d = 3.36*10**(-8);\t\t\t#diameter of the helium molecule in cm\n",
+      "\n",
+      "# Calculations\n",
+      "mf = 1/((2**(0.5))*3.14*(d**2)*n)\n",
+      "\n",
+      "# Result\n",
+      "print 'the mean free path of the hydrogen molecue is %.2e cm'%(mf)\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "the mean free path of the hydrogen molecue is 7.23e-06 cm\n"
+       ]
+      }
+     ],
+     "prompt_number": 20
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 4.16 page no : 141"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "# Variables\n",
+      "n = 85*10**(-6);\t\t\t#coefficent of vismath.cosity in dynes/cm**2/velocity gradient\n",
+      "c = 16*10**4;\t\t\t#velocity in cm/sec\n",
+      "p = 0.000089;\t\t\t#density in gm/cc\n",
+      "N = 6.06*10**23/22400;\t\t\t#avagadro number\n",
+      "a = (2)**(0.5)*(22./7);\t\t\t#constant\n",
+      "\n",
+      "# Calculations\n",
+      "mf = (3*n/(p*c));\t\t\t#mean free path in cm\n",
+      "cr = c/mf;\t\t\t#collision rate\n",
+      "d = (1/(a*N*mf))**(0.5);\t\t\t#molecular diameter of hydrogen gas in cm\n",
+      "\n",
+      "# Results\n",
+      "print 'the mean free path is %.2e cm  \\\n",
+      "\\nthe collision rate is %.1e  \\\n",
+      "\\nthe molecular diameter of hydrogen gas is %.1e cm'%(mf,cr,d)\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "the mean free path is 1.79e-05 cm  \n",
+        "the collision rate is 8.9e+09  \n",
+        "the molecular diameter of hydrogen gas is 2.2e-08 cm\n"
+       ]
+      }
+     ],
+     "prompt_number": 3
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 4.17 page no : 141"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "\n",
+      "# Variables\n",
+      "d = 2*10**(-8);\t\t\t#diameter of the molecule in cm\n",
+      "k = 1.38*10**(-6);\t\t\t#boltzmann constant in ergs/deg\n",
+      "t = 273;\t\t\t#temperature at ntp in K\n",
+      "p = 76*13.6*981;\t\t\t#pressure at ntp in gm/cm/sec**2\n",
+      "\n",
+      "# Calculations\n",
+      "mf = ((k*t)/(2**(0.5)*3.14*(d**2)*p));\t\t\t#mean free path in cm\n",
+      "\n",
+      "# Result\n",
+      "print 'mean free path at ntp is %.1e cm'%(mf)\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "mean free path at ntp is 2.1e+05 cm\n"
+       ]
+      }
+     ],
+     "prompt_number": 22
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 4.18 page no : 141"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "# Variables\n",
+      "t = 288;\t\t\t#temperature in K\n",
+      "k = 1.38*10**(-16);\t\t\t#boltzmann constant in erg/deg\n",
+      "N = 6.02*10**23;\t\t\t#avagadro number\n",
+      "m = 32/N;\t\t\t#mass of each oxygen molecule in gm\n",
+      "v = 196*10**-6;\t\t\t#viscosity in poise\n",
+      "\n",
+      "# Calculations\n",
+      "av = ((8*k*t/(3.14*m))**0.5);\t\t\t#average velocity in cm/sec\n",
+      "d = (m*av/(3*3.14*2**(0.5)*v))**0.5;\t\t\t#diameter of the molecule in cm\n",
+      "\n",
+      "# Results\n",
+      "print 'diameter of the molecule is %.1e cm'%(d)\n",
+      "print \"Note : answer is slightly different because of rounding error\""
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "diameter of the molecule is 3.0e-08 cm\n",
+        "Note : answer is slightly different because of rounding error\n"
+       ]
+      }
+     ],
+     "prompt_number": 2
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 4.19 page no : 142"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "\n",
+      "# Variables\n",
+      "mf = 15;\t\t\t#mean free path in cm\n",
+      "t = 300;\t\t\t#temperature of oxygen molecule in K\n",
+      "d = 3*10**(-8);\t\t\t#diameter of the molecule in cm\n",
+      "N = 6.02*10**23;\t\t\t#avagadro number\n",
+      "r = 8.32*10**7;\t\t\t#universal gas constant in ergs/mole/deg\n",
+      "a = (2**(0.5))*(22./7);\n",
+      "\n",
+      "#CALCULATIONS\n",
+      "p = (r*t)/(N*a*(d**2)*mf);\t\t\t#pressure of the oxygen molecule in dynes/sq.cm\n",
+      "\n",
+      "# Result\n",
+      "print 'the pressure of the oxygen molecule is %3.3f dynes/sq.cm'%(p)\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "the pressure of the oxygen molecule is 0.691 dynes/sq.cm\n"
+       ]
+      }
+     ],
+     "prompt_number": 27
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 4.20 pageno : 142"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "# Variables\n",
+      "k = 5.64*10**-14;\t\t\t#kinetic energy of the hydrogen molecule ergs\n",
+      "t = 273;\t\t\t#temperature of the oxygen molecule in K\n",
+      "r = 8.32*10**7;\t\t\t#universal gas constant in ergs \n",
+      "\n",
+      "# Calculations\n",
+      "N = (3./2)*(r*t/k);\t\t\t#avagadro number\n",
+      "\n",
+      "# Result\n",
+      "print 'the avagadro number is %.2e'%(N)\n",
+      "print \"Note : answer is slightly different because of rounding error\""
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "the avagadro number is 6.04e+23\n",
+        "Note : answer is slightly different because of rounding error\n"
+       ]
+      }
+     ],
+     "prompt_number": 30
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 4.21 pageno : 143"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "\n",
+      "# Variables\n",
+      "q = 5000;\t\t\t#total number of molecules\n",
+      "e = 2.7183;\t\t\t#constant value\n",
+      "t1 = 0.5;\t\t\t#distance travled to the mean free path\n",
+      "t2 = 1;\t\t\t#distance travelled to the mean free path\n",
+      "\n",
+      "#CALCULATONS\n",
+      "p1 = q*(e**-t1);\t\t\t#n0.of molecules having no collision in traversing a dismath.tance t1\n",
+      "p2 = q*(e**-t2);\t\t\t#n0.of molecules having no collision in traversing a dismath.tance t2\n",
+      "\n",
+      "#OUPUT\n",
+      "print 'the no. of molecules having no collision in traversing distance equal to 0.5 times the mean free path is %.f  \\\n",
+      "\\nthe no. of molecules having no collision in traversing a distance equal to 1 time the mean free path is %.f'%(p1,p2)\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "the no. of molecules having no collision in traversing distance equal to 0.5 times the mean free path is 3033  \n",
+        "the no. of molecules having no collision in traversing a distance equal to 1 time the mean free path is 1839\n"
+       ]
+      }
+     ],
+     "prompt_number": 5
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 4.22 page no  : 143"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "\n",
+      "# Variables\n",
+      "t = 38380;\t\t\t#temperature of the molecule in K\n",
+      "k = 1.38*10**-16;\t\t\t#boltzman consmath.tant of one electron in ergs/K\n",
+      "e = 1.6*10**-12;\t\t\t#charge of one electron volts\n",
+      "\n",
+      "#CALCULATIOS\n",
+      "mk = 1.5*k*t/e;\t\t\t#mean kinetic energy per atom in ev\n",
+      "\n",
+      "# Result\n",
+      "print 'the mean kinetic energy of the molecule is %3.2f ev'%(mk) \n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "the mean kinetic energy of the molecule is 4.97 ev\n"
+       ]
+      }
+     ],
+     "prompt_number": 32
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 4.23 pageno : 143"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "# Variables\n",
+      "v = 1.7*10**-4;\t\t\t#vismath.cosity of the air molecule in cgs\n",
+      "d = 0.00129;\t\t\t#density of the molecule in gm/ml\n",
+      "p = 76*13.6*981;\t\t\t#pressure of the molecule in gm/cm/sec**2\n",
+      "\n",
+      "# Calculations\n",
+      "r = (3*p/d)**(0.5);\t\t\t#rms velocity of the molecule in cm/sec\n",
+      "mf = (3*v/(d*r));\t\t\t#mean free path in cm\n",
+      "cf = r/mf;\t\t\t#collision frequency\n",
+      "\n",
+      "# Result\n",
+      "print 'the mean free path is %.1e cm  \\\n",
+      "\\nthe collision frequency is %.e'%(mf,cf)\n",
+      "print \"Note : answer is slightly different because of rounding error\""
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "the mean free path is 8.1e-06 cm  \n",
+        "the collision frequency is 6e+09\n",
+        "Note : answer is slightly different because of rounding error\n"
+       ]
+      }
+     ],
+     "prompt_number": 36
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 4.24 page no : 143"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "# The pressure of the gas\n",
+      "\n",
+      "# Variables\n",
+      "t2 = 296.4;\t\t\t#temperature of the first plate in K\n",
+      "t1 = 304.7;\t\t\t#temperature of the second plate in K\n",
+      "f = 1.6*10**-2;\t\t\t#force repelled cold is dynes/sq.cm\n",
+      "\n",
+      "# Calculations\n",
+      "p = (4*f*t2/(t1-t2));\t\t\t#pressure of the gas in dynes/sq.cm\n",
+      "\n",
+      "# Result\n",
+      "print 'the pressure of the gas is %3.3f dynes/sq.cm'%(p)\n",
+      "print \"Note : mistake in answer in book. Please calculate manually.\""
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "the pressure of the gas is 2.285 dynes/sq.cm\n",
+        "Note : mistake in answer in book. Please calculate manually.\n"
+       ]
+      }
+     ],
+     "prompt_number": 40
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 4.25 page no : 144"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "# Variables\n",
+      "mf = 28.5*10**-6;\t\t\t#mean free path in cm\n",
+      "d = 0.000178;\t\t\t#density of helium in gm/ml\n",
+      "m = 6*10**-24;\t\t\t#mass of the helium atom in gm\n",
+      "a = (2**(0.5))*3.14;\t\t\t#constant\n",
+      "\n",
+      "# Calculations\n",
+      "d = (m/(a*d*mf))**(0.5);\t\t\t#diameter of the size in cm\n",
+      "\n",
+      "# Result\n",
+      "print 'the size of the helium atom is %.2e cm'%(d)\n",
+      "print \"Note : answer is slightly different because of rounding error\""
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "the size of the helium atom is 1.63e-08 cm\n",
+        "Note : answer is slightly different because of rounding error\n"
+       ]
+      }
+     ],
+     "prompt_number": 42
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 4.26 page no : 144"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "\n",
+      "# Variables\n",
+      "a1 = 0*10**-4;\t\t\t#first horizontal print lacement in cm\n",
+      "a2 = 5.6*10**-4;\t\t\t#second horizontal print lacement in cm\n",
+      "a3 = -4.7*10**-4;\t\t\t#third horzontal print lacement in cm\n",
+      "a4 = -10.8*10**-4;\t\t\t#fourth horizontal print lacement in cm\n",
+      "a5 = 6.6*10**-4;\t\t\t#fifth horizontal print lacement print lacement in cm\n",
+      "a6 = -9.8*10**-4;\t\t\t#sixth horizontal print lacement in cm\n",
+      "a7 = -11.2*10**-4;\t\t\t#7th horizontal print lacement in cm\n",
+      "a8 = -4.0*10**-4;\t\t\t#8th horizontal print lacement in cm\n",
+      "a9 = 15.0*10**-4;\t\t\t#9thhorizontal print lacement in cm\n",
+      "a10 = 19.1*10**-4;\t\t\t#10th horizontal print lacement in cm\n",
+      "a11 = 16.0*10**-4;\t\t\t#11ht horizontal print lacement in cm\n",
+      "T = 293;\t\t\t#temperature of the particle in K\n",
+      "v = 0.01;\t\t\t#viscosity in cgs\n",
+      "r = 1.15*10**-5;\t\t\t#radius of the particle in cm\n",
+      "R = 8.32*10**7;\t\t\t#universal gas constant in kj/kg mole\n",
+      "t = 30;\t\t\t#time for observation of each in sec\n",
+      "\n",
+      "# Calculations\n",
+      "x = (a1**2+a2**2+a3**2+a4**2+a5**2+a6**2+a7**2+a8**2+a9**2+a10**2+a11**2)/11\n",
+      "n = R*T*t/(x*3*3.14*v*r);\t\t\t#no.of molecules in the observation \n",
+      "\n",
+      "# Result\n",
+      "print 'the value of n is %.1e'%(n)\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "the value of n is 5.7e+23\n"
+       ]
+      }
+     ],
+     "prompt_number": 43
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 4.27 page no : 144"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "# Variables\n",
+      "m = 6.*10**-24;\t\t\t#mass of the helium atom in gm\n",
+      "k =  1.38*10**-16;\t\t\t#boltzmann consmath.tant in erg\n",
+      "t1 = 100.;\t\t\t#temperature in K\n",
+      "t2 = 900.;\t\t\t#temperature in K\n",
+      "\n",
+      "# Calculations\n",
+      "r = (t1/t2)**(3./2)*(2.7183**(m*(1./(2*k))*10**8*(1-(1./9))));\t\t\t#fractional change in the no.of helium atoms\n",
+      "\n",
+      "#OUPUT\n",
+      "print 'the fractional change in the no.of helium atoms %.3f'%(r)\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "the fractional change in the no.of helium atoms 0.256\n"
+       ]
+      }
+     ],
+     "prompt_number": 45
+    }
+   ],
+   "metadata": {}
+  }
+ ]
+}
\ No newline at end of file
diff --git a/Heat_And_Thermodynamics/ch5.ipynb b/Heat_And_Thermodynamics/ch5.ipynb
new file mode 100755
index 00000000..13038a34
--- /dev/null
+++ b/Heat_And_Thermodynamics/ch5.ipynb
@@ -0,0 +1,140 @@
+{
+ "metadata": {
+  "name": ""
+ },
+ "nbformat": 3,
+ "nbformat_minor": 0,
+ "worksheets": [
+  {
+   "cells": [
+    {
+     "cell_type": "heading",
+     "level": 1,
+     "metadata": {},
+     "source": [
+      "Chapter 5 : Equations of state"
+     ]
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 5.1 pageno : 167"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "# Variables\n",
+      "t = 304;\t\t\t#temperature of the gas in k\n",
+      "p = 73;\t\t\t#pressure of the gas in atm\n",
+      "r = 0.00366;\t\t\t#universal gas constant in j/K/mole\n",
+      "\t\t\t#ct = 8a/27br;cp = a/27b**2\n",
+      "\n",
+      "# Calculations\n",
+      "b = (t*r/(8*p));\n",
+      "a = p*27*b**2;\n",
+      "\n",
+      "# Result\n",
+      "print 'the value of the constant b is %.5f  \\\n",
+      "\\nthe value of the constant a is %3.5f'%(b,a)\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "the value of the constant b is 0.00191  \n",
+        "the value of the constant a is 0.00715\n"
+       ]
+      }
+     ],
+     "prompt_number": 1
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 5.4 pageno : 169"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "# Variables\n",
+      "tc = 132;\t\t\t#critical temperature in K\n",
+      "pc = 37.2;\t\t\t#critical pressure in atm\n",
+      "r = 82.07;\t\t\t#universal gas constant in cm**3atm/mole/K\n",
+      "\n",
+      "# Calculations\n",
+      "a = 27*(r**2)*(tc**2)/(64*pc);\t\t\t#value of a in atm/cm**6/mol**2\n",
+      "b = r*tc/(8*pc);\t\t\t#value of b in cm**3/mol\n",
+      "\n",
+      "# Result\n",
+      "print 'the value of is %.2e atm/cm**6/mol**2  \\\n",
+      "\\nthe value of b is %3.2f cm**3/mol'%(a,b)\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "the value of is 1.33e+06 atm/cm**6/mol**2  \n",
+        "the value of b is 36.40 cm**3/mol\n"
+       ]
+      }
+     ],
+     "prompt_number": 5
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 5.5 pageno : 169"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "# Variables\n",
+      "p = 2.26*1.013*10**5;\t\t\t#critical pressure in N/m**2\n",
+      "v = 4./69;\t\t\t#critical volume in m**3/kmol\n",
+      "r = 8.31*10**3;\t\t\t#universal gas consmath.tant in J/kmol.K\n",
+      "\n",
+      "# Calculations\n",
+      "t = (8*p*v/(3*r));\t\t\t#critical temperature in K\n",
+      "\n",
+      "# Result\n",
+      "print 'critical temperature of the given problem is %3.2f K'%(t)\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "critical temperature of the given problem is 4.26 K\n"
+       ]
+      }
+     ],
+     "prompt_number": 6
+    }
+   ],
+   "metadata": {}
+  }
+ ]
+}
\ No newline at end of file
diff --git a/Heat_And_Thermodynamics/ch6.ipynb b/Heat_And_Thermodynamics/ch6.ipynb
new file mode 100755
index 00000000..2a03c0cd
--- /dev/null
+++ b/Heat_And_Thermodynamics/ch6.ipynb
@@ -0,0 +1,228 @@
+{
+ "metadata": {
+  "name": ""
+ },
+ "nbformat": 3,
+ "nbformat_minor": 0,
+ "worksheets": [
+  {
+   "cells": [
+    {
+     "cell_type": "heading",
+     "level": 1,
+     "metadata": {},
+     "source": [
+      "Chapter 6 : Change of state"
+     ]
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 6.1 page no : 194"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "# Variables\n",
+      "vl = 1;     \t\t\t#volume of water in cc\n",
+      "vs = 1.0908;\t\t\t#volume of ice in cc\n",
+      "t = 273;\t    \t\t#temperature in k\n",
+      "p = 76*13.6*981;\t\t#pressure in dynes/sq.cm\n",
+      "l = 80;\t\t\t        #latent heat of fusion in cal\n",
+      "j = 4.2*10**7;\t\t\t#joules consmath.tant in erg/cal\n",
+      "\n",
+      "# Calculations\n",
+      "v = vl-vs;\t\t\t        #change in volume\n",
+      "T = (v*t*p)/(j*l);\t\t\t#change in melting point of water\n",
+      "\n",
+      "# Result\n",
+      "print 'the change in melting point of water is %.5f'%(T)\n",
+      "print \"there is wrong answer printed in book. Please calculate manually.\""
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "the change in melting point of water is -0.00748\n",
+        "there is wrong answer printed in book. Please calculate manually.\n"
+       ]
+      }
+     ],
+     "prompt_number": 2
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 6.2 page no : 195"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "# Variables\n",
+      "vv = 1674.;\t\t\t#volume of vapour in cc\n",
+      "vl = 1.;\t\t\t    #volume of liquid in cc\n",
+      "p = 760.;\t\t\t#pressure of steam and water in mm\n",
+      "t = 373.;\t\t\t#temperature in K\n",
+      "p1 = 27.12;\t\t\t#superincumbent pressure in mm\n",
+      "\n",
+      "# Calculations\n",
+      "v = vv-vl;              \t\t\t#change in volume\n",
+      "l = (v*p1*t*0.024203/(p));\t\t\t#latent heat of vapourisation in cal\n",
+      "\n",
+      "# Result\n",
+      "print 'the latent heat of vapourisation is %3.1f cal'%(l)\n",
+      "print \"Note: Answer is slightly different because of rounding error.\"\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "the latent heat of vapourisation is 539.0 cal\n",
+        "Note: Answer is slightly different because of rounding error.\n"
+       ]
+      }
+     ],
+     "prompt_number": 6
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 6.3 page no : 195"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "\n",
+      "# Variables\n",
+      "m = 1./(342*100);\t\t\t#molar concentration of water\n",
+      "t = 289.;\t\t\t        #temperature in K\n",
+      "p = 53.5*13.6*981;\t\t\t#pressure in dynes/sq.cm\n",
+      "\n",
+      "# Calculations\n",
+      "k = p/(t*m);\t\t\t    #the value of k in ergs/mol.deg\n",
+      "\n",
+      "# Result\n",
+      "print 'the value of k is %.1e ergs/mol.deg'%(k)\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "the value of k is 8.4e+07 ergs/mol.deg\n"
+       ]
+      }
+     ],
+     "prompt_number": 7
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 6.4 pageno : 196"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "# Variables\n",
+      "p1 = 4.60;\t     \t\t    #presure at 0deg.C in mm per deg.C\n",
+      "p2 = 4.94;\t\t        \t#pressure at 1deg.C in mm per deg.C\n",
+      "t = 0.0072;\t\t\t        #lowering the melting point in deg.C\n",
+      "t1 = 7.1563979*10**(-3);\t\t\t#rise in melting point in deg.C\n",
+      "p = 760;\t\t\t        #atmospheric pressure in mm hg\n",
+      "\n",
+      "# Calculations\n",
+      "dp = p2-p1;\t\t\t        #rate of increase of pressure in mm per deg.C\n",
+      "p3 = (t1*p)/t;\t\t\t    #pressure in mm\n",
+      "dt = (755.4-p3)/dp;\t\t\t#tmperature for the triple point in deg.C\n",
+      "\n",
+      "# Result\n",
+      "print 'temperature for the triple point is %3.6f deg.C'%(dt)\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "temperature for the triple point is 0.007188 deg.C\n"
+       ]
+      }
+     ],
+     "prompt_number": 8
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 6.5 pageno : 196"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "# Variables\n",
+      "v = 21*10**4;\t\t\t#change in volume from vapour to liquid in cc\n",
+      "Ls = 687;\t\t\t#latent heat of sublimation in cal\n",
+      "lv = 607;\t\t\t#latent heat of vapourisation in cal\n",
+      "t = 273;\t\t\t#temperature of water in deg.C\n",
+      "j = 4.2*10**7;\t\t\t#joules constant in ergs/cal\n",
+      "\n",
+      "# Calculations\n",
+      "sv = lv*j/(t*(v));\t\t\t#slope of vapourisation curve at 0 deg.C in dyne/sq.cm/deg.C\n",
+      "ss = Ls*j/(t*(v));\t\t\t#slope of sublimation curve at 0 deg.C in dyne/sq.cm/deg.C\n",
+      "\n",
+      "# Result\n",
+      "print 'the slope of vapourisation curve is %.2e dyne/sq.cm/deg.C  \\\n",
+      "\\nthe slope of sublimation curve is %.2e dyne/sq.cm/deg.C'%(sv,ss)\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "the slope of vapourisation curve is 4.45e+02 dyne/sq.cm/deg.C  \n",
+        "the slope of sublimation curve is 5.03e+02 dyne/sq.cm/deg.C\n"
+       ]
+      }
+     ],
+     "prompt_number": 10
+    }
+   ],
+   "metadata": {}
+  }
+ ]
+}
\ No newline at end of file
diff --git a/Heat_And_Thermodynamics/ch7.ipynb b/Heat_And_Thermodynamics/ch7.ipynb
new file mode 100755
index 00000000..05fb5d54
--- /dev/null
+++ b/Heat_And_Thermodynamics/ch7.ipynb
@@ -0,0 +1,334 @@
+{
+ "metadata": {
+  "name": ""
+ },
+ "nbformat": 3,
+ "nbformat_minor": 0,
+ "worksheets": [
+  {
+   "cells": [
+    {
+     "cell_type": "heading",
+     "level": 1,
+     "metadata": {},
+     "source": [
+      "Chapter 7 : The joule thomson cooling efect"
+     ]
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 7.1 page no : 239"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "# Variables\n",
+      "t = 33.18;\t\t\t#critical temperature in K\n",
+      "pc = 12.80*76*981*13.6;\t\t\t#critical pressure in dynes/sq.cm\n",
+      "r = 83.15;\t\t\t#universal gas constant in kj/kg.K\n",
+      "d = 0.08987;\t\t\t#density of hydrogen in gm/lit\n",
+      "v = 2000/0.08987;\t\t\t#gram molecular volune of hydrogen in cc\n",
+      "\n",
+      "# Calculations\n",
+      "b = r*10**6*t/(8*pc);\t\t\t#vanderwaal constant in cm**3/mol\n",
+      "to = 2*27*t*(1-(b/v))/8;\t\t\t#inversion temperature of the hydrogen in K\n",
+      "\n",
+      "# Result\n",
+      "print 'the inversion temperature of hydrogen is %3.2f K'%(to)\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "the inversion temperature of hydrogen is 223.70 K\n"
+       ]
+      }
+     ],
+     "prompt_number": 1
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 7.2 pageno : 240"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "# Variables\n",
+      "b = 0.00136;\t\t\t#vanderwaal constant in suv/gm\n",
+      "a = 0.011;\t\t\t#vanderwaal constant in atm(suv)**2/gm**2\n",
+      "r = 0.003696;\t\t\t#universal gas constant in atm(suv)/gm.deg\n",
+      "t = 423;\t\t\t#temperature of steam in K\n",
+      "cp = -0.674/0.024205;\t\t\t#specific heat at 423K in atm(cc)gm(deg)\n",
+      "\n",
+      "# Calculations\n",
+      "dt = (-b+(2*a/(r*t)))/cp;\t\t\t#change of temperature per atm drop of pressure in deg/atm\n",
+      "\n",
+      "# Result\n",
+      "print 'the change of temperature per atmosphere drop of pressure is %3.7f deg/atm'%(dt)\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "the change of temperature per atmosphere drop of pressure is -0.0004565 deg/atm\n"
+       ]
+      }
+     ],
+     "prompt_number": 2
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 7.3 pageno : 241"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "# Variables\n",
+      "r = 8.3*10**7;\t\t\t#universal gas constant in ergs/deg.C\n",
+      "a = 1.36*10**6*76*13.6*981;\t\t\t#vanderwaal constant in atm.(suv**2)/(gm**2)\n",
+      "b = 32;\t\t\t#vanderwaal constant in cc\n",
+      "cp = 7.03;\t\t\t#specific heat at constant pressure in cal\n",
+      "j = 4.18*10**7;\t\t\t#joules constant in ergs/cal\n",
+      "t = 273;\t\t\t#temperature of the gas in K\n",
+      "\n",
+      "# Calculations\n",
+      "dt = ((2*a/(r*t))-b)*10**6/(cp*j);\t\t\t#change of temperature in atmosphere drop of pressure in deg/atm/cm**3\n",
+      "\n",
+      "# Result\n",
+      "print 'the change of temperature in atmosphere drop of pressure is %3.2f deg C/atm/cm**2'%(dt)\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "the change of temperature in atmosphere drop of pressure is 0.31 deg C/atm/cm**2\n"
+       ]
+      }
+     ],
+     "prompt_number": 2
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 7.4 pageno : 241"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "# Variables\n",
+      "u = 1.08;\n",
+      "cp = 8.6;\t    \t        \t#specific heat in kj/kg.K\n",
+      "j = 4.2;\t\t    \t        #joules constant in j/cal\n",
+      "p1 = 1*1.013*10**6;\t\t\t    #pressure at intial in N/sq.m\n",
+      "p2 = 20*1.013*10**6;\t\t\t#pressure at final in N/sq.m\n",
+      "\n",
+      "# Calculations\n",
+      "dh = -u*cp*j*(p1-p2);\t\t\t#change in enthalpy in joules\n",
+      "\n",
+      "# Result\n",
+      "print 'the change in enthalpy is %3.3e joules'%(dh)\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "the change in enthalpy is 7.508e+08 joules\n"
+       ]
+      }
+     ],
+     "prompt_number": 6
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 7.5 pageno : 241"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "# Variables\n",
+      "tc = 5.26;\t\t\t#critical temperature of the helium in K\n",
+      "\n",
+      "# Calculations\n",
+      "ti = 27*tc/4;\t\t\t#inversion temperature of the helium in K\n",
+      "\n",
+      "# Result\n",
+      "print 'the inversion temperature of the helium is %3.2f K'%(ti)\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "the inversion temperature of the helium is 35.50 K\n"
+       ]
+      }
+     ],
+     "prompt_number": 7
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 7.6 pageno : 241"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "# Variables\n",
+      "a = 0.245*10**6*10**6;\t\t\t#vanderwaal constant in cm**4.dyne/mole**2\n",
+      "b = 2.67*10;\t\t\t#vanderwaal constant in cc/mole\n",
+      "r = 2*4.2*10**7;\t\t\t#universal gas constant in ergs/mole.K\n",
+      "\n",
+      "# Calculations\n",
+      "ti = 2*a/(b*r);\t\t\t#inversion temperature in K\n",
+      "\n",
+      "# Result\n",
+      "print 'inversion temperature of hydrogen is %.f K'%(round(ti,-1))\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "inversion temperature of hydrogen is 220 K\n"
+       ]
+      }
+     ],
+     "prompt_number": 9
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 7.7 pageno : 242"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "# Variables\n",
+      "dp = 50*10**6;\t\t\t#change in pressure in dynes/sq.cm\n",
+      "cp = 7*4.2*10**7;\t\t\t#specific heat constant pressure in ergs/mole.K\n",
+      "a = 1.32*10**12;\t\t\t#vanderwaal constant in cm**4.dyne/mole**2\n",
+      "b = 31.2;\t\t\t#vanderwaal constant in cm**2/mole\n",
+      "t = 300;\t\t\t#inital temperature in K\n",
+      "r = 2*4.2*10**7;\t\t\t#ergs/mole.K\n",
+      "\n",
+      "# Calculations\n",
+      "dt = ((2*a/(r*t))-b)*dp/cp;\t\t\t#change in temperature in K\n",
+      "\n",
+      "# Result\n",
+      "print 'the change in temperature is %3.1f K'%(dt)\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "the change in temperature is 12.5 K\n"
+       ]
+      }
+     ],
+     "prompt_number": 11
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 7.8 pageno : 242"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "\n",
+      "# Variables\n",
+      "p1 = 1.;\t\t\t    #inital pressure in atm\n",
+      "p2 = 51.;   \t\t\t#final pressure in atm\n",
+      "t1 = 300.;\t    \t\t#inital temperature in K\n",
+      "y = 1.4;\t\t    \t#coefficient of expansion\n",
+      "\n",
+      "# Calculations\n",
+      "t2 = t1*(p2/p1)**((1-y)/y);\t\t\t#final temperature in K\n",
+      "dt = t1-t2;\t                \t\t#drop in temperature in K\n",
+      "\n",
+      "# Results\n",
+      "print 'the drop in temperature is %3.2f K'%(dt)\n",
+      "print \"Note : answer is slightly different because of rounding error\""
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "the drop in temperature is 202.45 K\n",
+        "Note : answer is slightly different because of rounding error\n"
+       ]
+      }
+     ],
+     "prompt_number": 16
+    }
+   ],
+   "metadata": {}
+  }
+ ]
+}
\ No newline at end of file
diff --git a/Heat_And_Thermodynamics/ch8.ipynb b/Heat_And_Thermodynamics/ch8.ipynb
new file mode 100755
index 00000000..c82c1776
--- /dev/null
+++ b/Heat_And_Thermodynamics/ch8.ipynb
@@ -0,0 +1,749 @@
+{
+ "metadata": {
+  "name": ""
+ },
+ "nbformat": 3,
+ "nbformat_minor": 0,
+ "worksheets": [
+  {
+   "cells": [
+    {
+     "cell_type": "heading",
+     "level": 1,
+     "metadata": {},
+     "source": [
+      "Chapter 8 : First law of thermodynamics"
+     ]
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 8.1 page no : 261\n"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "# Variables\n",
+      "l = 80;\t\t\t#latent heat of fusion in cal\n",
+      "j = 4.2*10**7;\t\t\t#joules constant in ergs/cal\n",
+      "w = -0.092*10**6;\t\t\t#work done in changing phase change in ergs\n",
+      "\n",
+      "# Calculations\n",
+      "q = l*j;\t\t\t#heat added in ergs\n",
+      "du = q-w;\t\t\t#internal energy in ergs\n",
+      "\n",
+      "# Result\n",
+      "print 'the change in internal energy is %.1e ergs'%(du)\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "the change in internal energy is 3.4e+09 ergs\n"
+       ]
+      }
+     ],
+     "prompt_number": 3
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 8.2 page no : 261"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "# Variables\n",
+      "m = 1.;\t        \t\t#mass in gm\n",
+      "l = 536.;\t\t    \t#latent heat in cal/gm\n",
+      "j = 4.2*10**7;\t\t\t#joules constant in ergs/cal\n",
+      "v = 1649;\t\t\t    #volume of water in cc\n",
+      "p = 76*13.6*981;\t\t#pressure of water in dynes/sq.cm\n",
+      "\n",
+      "# Calculations\n",
+      "dq = m*l*j;\t\t\t#heat supplied in ergs\n",
+      "dw = p*v;\t\t\t#work done in ergs\n",
+      "du = dq-dw;\t\t\t#internal energy developed in ergs\n",
+      "\n",
+      "# Result\n",
+      "print 'internal energy of water is %.2E ergs'%(du)\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "internal energy of water is 2.08E+10 ergs\n"
+       ]
+      }
+     ],
+     "prompt_number": 5
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 8.3 pageno : 261"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "# Variables\n",
+      "dv = 10;\t\t\t#ratio of original volume to final volume\n",
+      "t1 = 293;\t\t\t#inital temperature in K\n",
+      "y = 1.41;\t\t\t#coefficent of expansion\n",
+      "\n",
+      "# Calculations\n",
+      "t2 = t1*(dv)**(y-1);\t\t\t#final temperature in K\n",
+      "\n",
+      "# Result\n",
+      "print 'the final temperature is %.f K'%(t2)\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "the final temperature is 753 K\n"
+       ]
+      }
+     ],
+     "prompt_number": 7
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 8.4 pageno : 261"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "# Variables\n",
+      "t = 273;\t\t\t#temperature of earth at height h in K\n",
+      "p = 760;\t\t\t#pressure in mm of hg\n",
+      "dp = 1;\t\t\t#change in pressure in mm of hg\n",
+      "y = 1.418;\t\t\t#coefficient of expansion\n",
+      "\n",
+      "# Calculations\n",
+      "dt = ((y-1)/y)*dp*t/p;\t\t\t#change in temperature in deg.C\n",
+      "\n",
+      "# Result\n",
+      "print 'the change in temperature is %3.3f deg.C'%(dt)\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "the change in temperature is 0.106 deg.C\n"
+       ]
+      }
+     ],
+     "prompt_number": 8
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 8.5 pageno : 262"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "# Variables\n",
+      "p1 = 2;\t\t\t#pressure initial in atm\n",
+      "p2 = 1.;\t\t\t#pressure final in atm\n",
+      "t1 = 273 + 15;\t\t\t#inital temperature in K\n",
+      "y = 1.4;\t\t\t#coefficent of expansion\n",
+      "\n",
+      "# Calculations\n",
+      "t2 = t1*(p2/p1)**((y-1)/y);\t\t\t#final temperature in K\n",
+      "dt = t1-t2;\t\t\t#drop in temperature in K\n",
+      "\n",
+      "# Result\n",
+      "print 'drop in temperature is %3.2f K'%(dt)\n",
+      "print \"Note : answer is slightly different because of rounding error\""
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "drop in temperature is 51.74 K\n",
+        "Note : answer is slightly different because of rounding error\n"
+       ]
+      }
+     ],
+     "prompt_number": 12
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 8.6 pageno : 262"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "# Variables\n",
+      "t1 = 288;\t\t\t#inital temperature in K\n",
+      "dv = 1./2;\t\t\t#ratio of inital to final volume\n",
+      "y = 1.4;\t\t\t#coefficient of expansion\n",
+      "\n",
+      "# Calculations\n",
+      "t2 = t1*(dv)**(y-1);\t\t\t#final temperature in K\n",
+      "\n",
+      "# Result\n",
+      "print 'the final temperature is %3.1f K'%(t2)\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "the final temperature is 218.3 K\n"
+       ]
+      }
+     ],
+     "prompt_number": 13
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 8.7 pageno : 262"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "# Variables\n",
+      "y = 1.4;\t\t\t#coefficent of exapnsion\n",
+      "p1 = 1;\t\t\t#standard pressure in atm\n",
+      "dv = 50;\t\t\t#ratio of initial volume to final volume\n",
+      "t1 = 273;\t\t\t#standard temperature in K\n",
+      "\n",
+      "# Calculations\n",
+      "p2 = p1*dv;\t\t\t#final pressure when slowly compressed in atm\n",
+      "p3 = p1*(dv)**(y);\t\t\t#final pressure when suddenly compressed in atm\n",
+      "t2 = t1*(dv)**(y-1);\t\t\t#rise in temperature when it is suddenly compressed in K\n",
+      "\n",
+      "# Result\n",
+      "print 'the final pressure when it is compressed slowly is %.f atm  \\\n",
+      "\\nthe final pressure when it is compressed suddenly is %.f atm  \\\n",
+      "\\nthe rise in temperature when it is suddenly compressed is %.0f K'%(p2,p3,t2)\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "the final pressure when it is compressed slowly is 50 atm  \n",
+        "the final pressure when it is compressed suddenly is 239 atm  \n",
+        "the rise in temperature when it is suddenly compressed is 1305 K\n"
+       ]
+      }
+     ],
+     "prompt_number": 14
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 8.8 pageno : 263"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "# Variables\n",
+      "y = 1.5;\t\t\t#coefficient of expansion\n",
+      "dp = 1./8;\t\t\t#ratio of inital pressure to final pressure\n",
+      "t1 = 300;\t\t\t#inital tempreature in K\n",
+      "\n",
+      "# Calculations\n",
+      "t2 = t1*(dp)**((1-y)/y);\t\t\t#change in temperature in K\n",
+      "t3 = t2-t1;\t\t\t#rise in temperature in K\n",
+      "\n",
+      "# Result\n",
+      "print 'the rise in temperature is %3.2f K'%(t3)\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "the rise in temperature is 300.00 K\n"
+       ]
+      }
+     ],
+     "prompt_number": 15
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 8.9 pageno : 263"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "import math\n",
+      "\n",
+      "# Variables\n",
+      "t1 = 400;\t\t\t#inital temperature in K\n",
+      "dv = 2;\t\t\t#ratio of volumes final and inital\n",
+      "r = 8.31*10**7;\t\t\t#universal gas constant in ergs/kg.K\n",
+      "\n",
+      "# Calculations\n",
+      "w = r*t1*math.log(2);\t\t\t#work done in expanding isothermally in ergs\n",
+      "\n",
+      "# Result\n",
+      "print 'the work done in expanding isothermally is %.1e ergs'%(w)\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "the work done in expanding isothermally is 2.3e+10 ergs\n"
+       ]
+      }
+     ],
+     "prompt_number": 17
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 8.10 page no : 263"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "# Variables\n",
+      "p1 = 76;\t\t\t#inital pressure in cm\n",
+      "t1 = 290;\t\t\t#inital temperature in K\n",
+      "y = 1.4;\t\t\t#coefficent of expansion\n",
+      "dv = 2;\t\t\t#ratio of inital to fianl volume when air expands isothermally \n",
+      "dv1 = 2;\t\t\t#ratio of inital to final volume when air expands adiabatically\n",
+      "\n",
+      "# Calculations\n",
+      "p2 = p1/dv;\t\t\t#final pressure when air expands isothermally in cm of hg\n",
+      "t2 = t1;\t\t\t#final temperature when air expands isothermally in K\n",
+      "t3 = t2*(1./dv1)**(y-1);\t\t\t#temprature when air expands adiabatically in K\n",
+      "p3 = p2*(1./dv1)**(y);\t\t\t#final pressure when air expands adiabatically in mm of hg\n",
+      "\n",
+      "# Result\n",
+      "print 'final pressure when air expands isothermally in cm of hg %3.2f mm of hg  \\\n",
+      "\\nfinal temperature when air expands isothermally is %3.2f K  \\\n",
+      "\\ntemprature when air expands adiabatically is %3.1f K  \\\n",
+      "\\nfinal pressure when air expands adiabatically is %3.2f cm of mercury'%(p2,t2,t3,p3)\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "final pressure when air expands isothermally in cm of hg 38.00 mm of hg  \n",
+        "final temperature when air expands isothermally is 290.00 K  \n",
+        "temprature when air expands adiabatically is 219.8 K  \n",
+        "final pressure when air expands adiabatically is 14.40 cm of mercury\n"
+       ]
+      }
+     ],
+     "prompt_number": 21
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 8.11 pageno : 264"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "# Variables\n",
+      "p = 76*13.6*981;\t\t\t#pressure of air in dynes/sq.cm\n",
+      "v = 11100.;\t\t\t#volume expanded in ml\n",
+      "t1 = 273.;\t\t\t#inital temperature in K\n",
+      "t2 = 274.;\t\t\t#final temperature in K\n",
+      "cv = 2.411;\t\t\t#specific heat at constant volume in cal/K\n",
+      "j = 4.2*10**7;\t\t\t#joules constant in ergs/cal\n",
+      "\n",
+      "# Calculations\n",
+      "w = p*v*math.log(t2/t1);\t\t\t#work done in ergs\n",
+      "h = cv*(t2-t1)+w/j;\t\t\t        #heat supplied in cal\n",
+      "\n",
+      "# Result\n",
+      "print 'the work done is %3.3e erg  \\\n",
+      "\\nthe heat supplied is %3.3f cal'%(w,h)\n",
+      "print \"Note : answer is different because of rounding error\""
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "the work done is 4.115e+07 erg  \n",
+        "the heat supplied is 3.391 cal\n",
+        "Note : answer is different because of rounding error\n"
+       ]
+      }
+     ],
+     "prompt_number": 25
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 8.12 pageno : 264"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "# Variables\n",
+      "p = 10**6;\t\t\t#pressure of air in dynes\n",
+      "d = 0.0001293;\t\t\t#density of air in gm/cc\n",
+      "t1 = 273;\t\t\t#inital temperature in K\n",
+      "dv = 2;\t\t\t#ratio of inital volume to final volume\n",
+      "y = 1.4;\t\t\t#coefficient of expansion\n",
+      "\n",
+      "# Calculations\n",
+      "r = p/(d*t1);\t\t\t#universal gas constant in dynes.cc/gm.K\n",
+      "t2 = round(t1*(dv)**(y-1));\t\t\t#final temperature in K\n",
+      "w = r*(t2-t1)/(y-1);\t\t\t#work done in adiabatic compression in ergs\n",
+      "\n",
+      "# Result\n",
+      "print 'work done in adiabatic compression is %.3e ergs'%(w)\n",
+      "print \"Note : answer is different because of rounding error\""
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "work done in adiabatic compression is 6.162e+09 ergs\n",
+        "Note : answer is different because of rounding error\n"
+       ]
+      }
+     ],
+     "prompt_number": 31
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 8.13 pageno : 265"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "# Variables\n",
+      "m = 5;\t\t\t#mass of air in gm\n",
+      "cv = 0.172;\t\t\t#specific heat at consmath.tant volume cal/gm\n",
+      "dt = 10;\t\t\t#changi in temperature in K\n",
+      "\n",
+      "# Calculations\n",
+      "ie = m*cv*dt;\t\t\t#change in internal energy in cal\n",
+      "\n",
+      "# Result\n",
+      "print 'change in internal energy is %3.2f cal'%(ie)\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "change in internal energy is 8.60 cal\n"
+       ]
+      }
+     ],
+     "prompt_number": 32
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 8.14 pageno : 265"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "# Variables\n",
+      "v1 = 10**3;\t\t\t#inital volume in cc\n",
+      "v2 = 2*v1;\t\t\t#final volume in cc\n",
+      "p1 = 76*13.6*981;\t\t\t#pressure in dyne/sq.cm\n",
+      "t1 = 273;\t\t\t#intial temperature in K\n",
+      "d = 1.29;\t\t\t#density of the gas gm/lit\n",
+      "cv = 0.168;\t\t\t#specific heat at constant volume in cal/gm\n",
+      "\n",
+      "# Calculations\n",
+      "t2 = (v2/v1)*t1;\t\t\t#final temperature in K\n",
+      "r = 0.068;\t\t\t#universal gas consmath.tant in cal\n",
+      "cp = cv+r;\t\t\t#specific heat at constant pressure in cal\n",
+      "q = d*cp*(t2-t1);\t\t\t#heat supplied in cal\n",
+      "\n",
+      "# Result\n",
+      "print 'the heat supplied to the gas is %3.2f cal'%(q)\n",
+      "print \"Note: answer is slightly different because of rounding error.\""
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "the heat supplied to the gas is 83.11 cal\n",
+        "Note: answer is slightly different because of rounding error.\n"
+       ]
+      }
+     ],
+     "prompt_number": 36
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 8.15 pageno : 165"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "# Variables\n",
+      "t = 303;\t\t\t#temperature of the one mole of the argon in K\n",
+      "v1 = 1;\t\t\t#intial volume in litres\n",
+      "v2 = 10;\t\t\t#final volume in litres\n",
+      "r = 8.31*10**7;\t\t\t#universal gas constant in ergs/K.mol\n",
+      "\n",
+      "# Calculations\n",
+      "w = r*t*math.log(v2/v1);\t\t\t#work done in isothermal expansion in ergs\n",
+      "\n",
+      "# Result\n",
+      "print 'the work done in isothermal expansion is %.1e ergs'%(w)\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "the work done in isothermal expansion is 5.8e+10 ergs\n"
+       ]
+      }
+     ],
+     "prompt_number": 38
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 8.16 pageno : 266"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "# Variables\n",
+      "dv = 4;\t\t\t#final volume of neon in lit\n",
+      "t = 273;\t\t\t#temperature of the gas in K\n",
+      "n = 2.6/22.4;\t\t\t#the no.of moles of neon\n",
+      "r = 1.98;\t\t\t#universal gas constant in cal/K.mol\n",
+      "\n",
+      "# Calculations\n",
+      "w = n*t*r*math.log(dv);\t\t\t#work done by gas in ergs\n",
+      "\n",
+      "# Result\n",
+      "print 'the work done by 2.6lit of neon is %3.2f ergs'%(w)\n",
+      "print \"Note: answer is slightly different because of rounding error.\""
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "the work done by 2.6lit of neon is 86.98 ergs\n",
+        "Note: answer is slightly different because of rounding error.\n"
+       ]
+      }
+     ],
+     "prompt_number": 40
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 8.18 page no : 266"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "import math\n",
+      "\n",
+      "# Variables\n",
+      "dv = 10**(-3);\t\t\t#ratio of initial and final volume\n",
+      "t1 = 10**5;\t\t\t#initial temperature in K\n",
+      "y = 1.66;\t\t\t#coefficient of expansion\n",
+      "\n",
+      "# Calculations\n",
+      "t2 = t1*((4./3*math.pi*10**12)/(4./3*math.pi*10**15))**(y-1);\t\t\t#final temperature in K\n",
+      "\n",
+      "# Result\n",
+      "print 'final temperature of the gas is %3.2f K'%(t2)\n",
+      "print \"Note : Answer in book is wrong. Please calculate manually.\""
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "final temperature of the gas is 1047.13 K\n",
+        "Note : Answer in book is wrong. Please calculate manually.\n"
+       ]
+      }
+     ],
+     "prompt_number": 46
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 8.19 pageno : 267"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "# Variables\n",
+      "p1 = 8.;\t\t\t#intial pressure in cm of hg\n",
+      "p2 = 6.;\t\t\t#final pressure in cm of hg\n",
+      "v1 = 1000.;\t\t\t#intial volume in cc\n",
+      "v2 = 1190.;\t\t\t#final volume in cc\n",
+      "\n",
+      "# Calculations\n",
+      "y = math.log(p1/p2)/math.log(v2/v1);\t\t\t#coefficient of expansion\n",
+      "\n",
+      "# Result\n",
+      "print 'the coefficent of expansion is %3.2f'%(y)\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "the coefficent of expansion is 1.65\n"
+       ]
+      }
+     ],
+     "prompt_number": 42
+    }
+   ],
+   "metadata": {}
+  }
+ ]
+}
\ No newline at end of file
diff --git a/Heat_And_Thermodynamics/ch9.ipynb b/Heat_And_Thermodynamics/ch9.ipynb
new file mode 100755
index 00000000..00373b6e
--- /dev/null
+++ b/Heat_And_Thermodynamics/ch9.ipynb
@@ -0,0 +1,597 @@
+{
+ "metadata": {
+  "name": ""
+ },
+ "nbformat": 3,
+ "nbformat_minor": 0,
+ "worksheets": [
+  {
+   "cells": [
+    {
+     "cell_type": "heading",
+     "level": 1,
+     "metadata": {},
+     "source": [
+      "Chapter 9 : Second law of thermodynamics"
+     ]
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 9.1 pageno : 308"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "# Variables\n",
+      "t2 = 300;\t\t\t#temperature of the math.sink in K\n",
+      "n1 = 0.4;\t\t\t#efficiency of the engine\n",
+      "n2 = 0.6;\t\t\t#efficiency of the engine\n",
+      "\n",
+      "# Calculations\n",
+      "t1 = t2/(1-n1);\t\t\t#temperature of the source in K\n",
+      "t3 = t2/(1-n2);\t\t\t#temperature of the source in K\n",
+      "\n",
+      "# Result\n",
+      "print 'the temperature of the source when 0.4 efficiency is %3.2f K  \\\n",
+      "\\nthe temperature of the source when 0.6 efficiency is %3.2f K'%(t1,t3)\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "the temperature of the source when 0.4 efficiency is 500.00 K  \n",
+        "the temperature of the source when 0.6 efficiency is 750.00 K\n"
+       ]
+      }
+     ],
+     "prompt_number": 1
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 9.2 pageno : 308"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "# Variables\n",
+      "t2 = 273.;\t\t\t#temperature of the math.sink in K\n",
+      "t1 = 373.;\t\t\t#temperature of the source in K\n",
+      "q1 = 840.;\t\t\t#heat supplied in joules\n",
+      "j = 4.2;\t\t\t#joukes constant in erg/cal\n",
+      "\n",
+      "# Calculations\n",
+      "w = (q1/t1)*(t1-t2);\t\t\t#work done in joules\n",
+      "q2 = (q1/j)*(t2/t1);\t\t\t#heat rejected in calories\n",
+      "n = 1-(t2/t1);\t\t\t#efficiency of the engine\n",
+      "\n",
+      "# Result\n",
+      "print 'work done is %3.f j  \\\n",
+      "\\nheat rejected is %3.f cal  \\\n",
+      "\\nthe efficiency of the engine is %3.1f %%'%(w,q2,n*100)\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "work done is 225 j  \n",
+        "heat rejected is 146 cal  \n",
+        "the efficiency of the engine is 26.8 %\n"
+       ]
+      }
+     ],
+     "prompt_number": 3
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 9.3 pageno : 309"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "# Variables\n",
+      "t1 = 90.;\t\t\t#temperature of the oxygen boils in K\n",
+      "t2 = 20.;\t\t\t#temperature of the liquid hydrogen in K\n",
+      "t3 = 300.;\t\t\t#temperature of the sink in K\n",
+      "\n",
+      "# Calculations\n",
+      "n = (t1-t2)/t1;\t\t\t#efficiency of the engine\n",
+      "t4 = t3/(1-n);\t\t\t#temperature of the source in K\n",
+      "\n",
+      "# Result\n",
+      "print 'the efficiency of the engine is %3.2f  \\\n",
+      "\\nthe temperature of the source is %3.2f K'%(n,t4)\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "the efficiency of the engine is 0.78  \n",
+        "the temperature of the source is 1350.00 K\n"
+       ]
+      }
+     ],
+     "prompt_number": 4
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 9.4 pageno : 309"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "# Variables\n",
+      "t1 = 373.;\t    \t    \t#temperature of the source in K\n",
+      "t2 = 273.;\t\t    \t    #temperature of the sink in K\n",
+      "w = 1200*10**5*980;\t\t\t#work done in ergs\n",
+      "j = 4.18*10**7;\t\t    \t#joules constant in ergs/cal\n",
+      "\n",
+      "# Calculations\n",
+      "q = (w/j)*(t1/(t1-t2));\t\t\t#heat added in cal\n",
+      "\n",
+      "# Result\n",
+      "print 'the heat added is %3.2f cal'%(round(q,-1))\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "the heat added is 10490.00 cal\n"
+       ]
+      }
+     ],
+     "prompt_number": 6
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 9.5 pageno : 309"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "# Variables\n",
+      "t1 = 273.;\t\t\t#temperature of the source in K\n",
+      "t2 = 290.;\t\t\t#temperature of the sink in K\n",
+      "l = 8*10.**11;\t\t\t#latent of fusion in ergs/cal\n",
+      "\n",
+      "# Calculations\n",
+      "n = (t2-t1)/t1;\t\t\t#efficiency of the engine\n",
+      "w = n*l;\t\t\t#energy to be supplied in ergs\n",
+      "\n",
+      "# Result\n",
+      "print 'efficiency of the engine is %.2f %%  \\\n",
+      "\\nenergy to be supplied is %.3e ergs'%(n*100,w)\n",
+      "print \"Note: answer in book are wrong please calculate manually.\""
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "efficiency of the engine is 6.23 %  \n",
+        "energy to be supplied is 4.982e+10 ergs\n",
+        "Note: answer in book are wrong please calculate manually.\n"
+       ]
+      }
+     ],
+     "prompt_number": 12
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 9.6 pageno : 309"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "\n",
+      "# Variables\n",
+      "t1 = 373;\t\t\t#temperature in K\n",
+      "t2 = 273;\t\t\t#temperature of math.sink in K\n",
+      "q = 10**4;\t\t\t#heat taken at higher temperature in cal\n",
+      "j = 4.2*10**7;\t\t\t#joules consmath.tant in ergs/cal\n",
+      "\n",
+      "# Calculations\n",
+      "w = q*j*(t1-t2)/t1;\t\t\t#work done in ergs\n",
+      "\n",
+      "# Result\n",
+      "print 'work done is %.1e ergs'%(w)\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "work done is 1.1e+11 ergs\n"
+       ]
+      }
+     ],
+     "prompt_number": 14
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 9.7 page no : 310"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "import math\n",
+      "\n",
+      "# Variables\n",
+      "p = 100*746/4.2;\t\t\t#power developed in cal/sec\n",
+      "t1 = 300.;\t\t\t#temperature of the sink in K\n",
+      "t2 = 500.\n",
+      "\n",
+      "# Calculations\n",
+      "te = 1 - (t1/t2)\n",
+      "Q1 = p * 100/40        # heat supplied\n",
+      "Q2 = Q1 * 0.6\n",
+      "\n",
+      "\n",
+      "# Result\n",
+      "print \"Thermal efficiency = %.f %%\"%(te*100)\n",
+      "print \"Power developed by the engine %.2f calories/sec\"%p\n",
+      "print \"If Q1 heat supplied , Q1 = %.2e cal/sec\"%Q1\n",
+      "print \"Q2 = %.2e cal/sec\"%Q2"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "Thermal efficiency = 40 %\n",
+        "Power developed by the engine 17761.90 calories/sec\n",
+        "If Q1 heat supplied , Q1 = 4.44e+04 cal/sec\n",
+        "Q2 = 2.66e+04 cal/sec\n"
+       ]
+      }
+     ],
+     "prompt_number": 23
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 9.8 page no : 310"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "import math \n",
+      "\n",
+      "# Variables\n",
+      "l = 964.8;\t\t\t#latent heat of steam in B.Th.U per lb\n",
+      "q = 4*15*l*778;\t\t\t#heat developed in ft lbs\n",
+      "w = 30000*60;\t\t\t#work done is ft lbs\n",
+      "pv = 12*1.013*10**6*10**3 \n",
+      "T = 600                # K\n",
+      "\n",
+      "# Calculations\n",
+      "n = (w/q)*100;\t\t\t#efficiency of the engine\n",
+      "p = 100-n;\t\t\t#percentage of heat wasted\n",
+      "T2 = 600./(6**.4)\n",
+      "R = pv/T\n",
+      "W = R * (T - T2) * 2.303 * math.log10(6)\n",
+      "e = 1 - (T2/T)\n",
+      "# Result\n",
+      "print \"Lowest temperature T2 = %.f K\"%T2\n",
+      "print \"Work done W = %.2e ergs\"%W\n",
+      "print \"Efficiency = %.1f %%\"%(e*100)"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "Lowest temperature T2 = 293 K\n",
+        "Work done W = 1.11e+10 ergs\n",
+        "Efficiency = 51.2 %\n"
+       ]
+      }
+     ],
+     "prompt_number": 34
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 9.9 page no : 311"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "# Variables\n",
+      "l=964.8;            #latent heat of steam in B.Th.U per lb\n",
+      "q=4*15*l*778;       #heat developed in ft lbs\n",
+      "w=33000*60;         #work done is ft lbs\n",
+      "\n",
+      "#CALCULATIONS\n",
+      "n=(w/q)*100;       #efficiency of the engine\n",
+      "p=100-n;          #percentage of heat wasted\n",
+      "\n",
+      "# Results\n",
+      "print ('the percentage of the heat wasted is %3.2f'%p)\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "the percentage of the heat wasted is 95.60\n"
+       ]
+      }
+     ],
+     "prompt_number": 49
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 9.10 page no : 311"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "# Variables\n",
+      "ip = 16.3*500*778/33000;\t\t\t# Variables power of the engine in HP\n",
+      "me = 0.72;\t\t\t#mechanical efficiency of the engine\n",
+      "bhp = 31;\t\t\t#brake horse power in b.h.p\n",
+      "ihp = bhp/me;\t\t\t#indicated horse power in HP\n",
+      "\n",
+      "# Calculations\n",
+      "i = ihp/ip;\t\t\t#indicated thermal efficiency\n",
+      "\n",
+      "# Result\n",
+      "print 'the indicted thermal efficiency is %3.2f %%'%(i*100)\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "the indicted thermal efficiency is 22.41 %\n"
+       ]
+      }
+     ],
+     "prompt_number": 4
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 9.11 pageno : 312"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "# Variables\n",
+      "p = 200.;\t\t\t#horse power of steam engine in lbs coal per hour\n",
+      "j = 770.;\t\t\t#joules constant in ft lbs per B.Th.U\n",
+      "\n",
+      "# Calculations\n",
+      "w = 12500*p*j;\t\t\t#equivalent work in ft.lb.per.hr\n",
+      "hp = w/(60*33000);\t\t\t#horse power\n",
+      "\n",
+      "# Result\n",
+      "print 'horse power of the engine is %3.2f'%(hp)\n",
+      "print \"Note : answer in book is wrong. Please check manually.\""
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "horse power of the engine is 972.22\n",
+        "Note : answer in book is wrong. Please check manually.\n"
+       ]
+      }
+     ],
+     "prompt_number": 5
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 9.12 pageno  : 312"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "# Variables\n",
+      "t1 = 340.;\t\t\t#temperature of the atmosphere in K\n",
+      "t2 = 612.;\t\t\t#temperature of the compression stroke in K\n",
+      "y = 1.39;\t\t\t#adiabatic expansion \n",
+      "t3 = 2040.;\t\t\t#temperature after consmtant volume ignition in K\n",
+      "\n",
+      "# Calculations\n",
+      "d = (t2/t1)**(1/(y-1))\t\t\t#density in gm/cc\n",
+      "n = 1-(1/d)**(y-1);\t\t    \t#efficiency of the engine\n",
+      "p = ((d)**(y))*(t3/t2);\t\t\t#maximum temperature of the temperature in atm\n",
+      "\n",
+      "# Result\n",
+      "print 'the maximum pressure of the engine is %3.f atm'%(p)\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "the maximum pressure of the engine is  27 atm\n"
+       ]
+      }
+     ],
+     "prompt_number": 43
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 9.13 pageno : 313"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "# Variables\n",
+      "t1 = 915;\t\t\t#temperature at the beggining in K\n",
+      "t2 = 2040;\t\t\t#temperature at the end in K\n",
+      "d = 12.6;\t\t\t#adiabatic expansion ratio\n",
+      "y = 1.39;\t\t\t#coefficent of expansion\n",
+      "\n",
+      "# Calculations\n",
+      "x = t2/t1                               \t\t\t#ratio temparatures\n",
+      "n = 1-(1/d)**(y-1)*((x**y)-1)/(y*(x-1));\t\t\t#efficiency of the engine\n",
+      "\n",
+      "# Result\n",
+      "print 'the efficiency of the engine is %3.3f'%(n)\n",
+      "print \"Note : answer slighty different because of rounding error\"\n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "the efficiency of the engine is 0.566\n",
+        "Note : answer slighty different because of rounding error\n"
+       ]
+      }
+     ],
+     "prompt_number": 40
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 9.14 pageno : 313"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "\n",
+      "# Variables\n",
+      "p1 = 15.;\t\t\t#intial pressure in lb/sq.inch\n",
+      "dv = 15.;\t\t\t#ratio of intial to final volume\n",
+      "t1 = 520.;\t\t\t#temperature at intial in K\n",
+      "y = 1.4;\t\t\t#coefficient of expansion\n",
+      "\n",
+      "# Calculations\n",
+      "p2 = p1*(dv)**(y);\t\t\t#final pressure in lb/sq.inch\n",
+      "t2 = t1*(dv)**(y-1);\t\t\t#final temperatire in K\n",
+      "\n",
+      "# Result\n",
+      "print 'the final pressure is %3.2f lb/sq.inch  \\\n",
+      "\\nthe final temperature is %.f K'%(p2,t2)"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "the final pressure is 664.69 lb/sq.inch  \n",
+        "the final temperature is 1536 K\n"
+       ]
+      }
+     ],
+     "prompt_number": 6
+    }
+   ],
+   "metadata": {}
+  }
+ ]
+}
\ No newline at end of file
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diff --git a/Heat_And_Thermodynamics/screenshots/chapter_6.png b/Heat_And_Thermodynamics/screenshots/chapter_6.png
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diff --git a/Heat_And_Thermodynamics/screenshots/temperature_of_the_source.png b/Heat_And_Thermodynamics/screenshots/temperature_of_the_source.png
new file mode 100755
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