{
 "metadata": {
  "name": "",
  "signature": "sha256:796b0d55d49c3a8708377f5eda9102cc03f40afdc4e2bd80f2e4fc59de97aea2"
 },
 "nbformat": 3,
 "nbformat_minor": 0,
 "worksheets": [
  {
   "cells": [
    {
     "cell_type": "heading",
     "level": 1,
     "metadata": {},
     "source": [
      "Chapter 4 : The First Law of Thermodynamics for Systems-Pure Substances"
     ]
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Example 4.1 Page No : 93"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "\t\t\t\n",
      "# Variables\n",
      "#four heat transfer\n",
      "Q_1 = 900 \t\t\t#J\n",
      "Q_2 = 80 \t\t\t#J\n",
      "Q_3 = -800 \t\t\t#J\n",
      "Q_4 = 150 \t\t\t#J\n",
      "#four work interactions\n",
      "W_1 = 200 \t\t\t#J\n",
      "W_2 = 150 \t\t\t#J\n",
      "W_3 = 300 \t\t\t#J\n",
      "\t\t\t#W_4\n",
      "\t\t\t\n",
      "# Calculations and Results\n",
      "W_4 = Q_1 +Q_2 +Q_3 +Q_4 -W_1 -W_2 -W_3  \n",
      "print \"Magnitude and Direction of the fourth work interaction, W4 = %.0f J\"%(W_4)\n"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "Magnitude and Direction of the fourth work interaction, W4 = -320 J\n"
       ]
      }
     ],
     "prompt_number": 1
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Example 4.2 Page No : 94"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "\t\t\t\n",
      "# Variables\n",
      "Q_a = -50 \t\t\t#KJ \t\t\t#heat transferred from the system along path A\n",
      "W_a = -65 \t\t\t#KJ \t\t\t#work done along path A\n",
      "Q_b = 0 \t\t\t#KJ \t\t\t#heat transferred from the system along path B\n",
      "\t\t\t#W_b work done along path B\n",
      "\n",
      "\t\t\t\n",
      "# Calculations and Results\n",
      "\n",
      "#Part(a)\n",
      "print \"Part a\";\n",
      "delE_a = Q_a - W_a \t\t\t#KJ \t\t\t#Change in energy along path A\n",
      "print \"Change in energy of the system = %.0f KJ\"%(delE_a);\n",
      "\n",
      "#Part(b)\n",
      "print \"Part b\";\n",
      "delE_b = -1*delE_a \t\t\t#KJ \t\t\t#Change in energy along path B\n",
      "W_b = delE_b - Q_b \t\t\t#KJ \t\t\t#work done along path B\n",
      "print \"Magnitude and direction of work done during B, W_b = %.0f KJ\"%(W_b)\n"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "Part a\n",
        "Change in energy of the system = 15 KJ\n",
        "Part b\n",
        "Magnitude and direction of work done during B, W_b = -15 KJ\n"
       ]
      }
     ],
     "prompt_number": 2
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Example 4.3 Page No : 99"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "\n",
      "\n",
      "# Variables\n",
      "m = 2.3 \t\t\t#kg \t\t\t#mass of substance\n",
      "u = 21 * 10**3 \t\t\t#J/kg \t\t\t#internal energy\n",
      "V = 110. \t\t\t#m/s \t\t\t#velocity \n",
      "z = 1500. \t\t\t#m \t\t\t#elevation above sea level\n",
      "g = 9.81 \t\t\t#m/s**2 \t\t\t#acceleration due to gravity\n",
      "\n",
      "\n",
      "\t\t\t\n",
      "# Calculations and Results\n",
      "E = m*(g*z + V**2/2 + u) \t\t\t#J/kg \t\t\t#Total energy of the system\n",
      "print \"The total energy of the system with respect to an observer at rest at sea level, E = %.4f KJ\"%(0.001*E);\n"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "The total energy of the system with respect to an observer at rest at sea level, E = 96.0595 KJ\n"
       ]
      }
     ],
     "prompt_number": 4
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Example 4.4 Page No : 103"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "from numpy import *\n",
      "from sympy import Derivative\n",
      "\t\t\t\n",
      "# Variables\n",
      "t = poly1d(0); \t\t\t#C \t\t\t#Temperature in C\n",
      "u = 196. + .718*t; \t\t\t#KJ/kg \t\t\t#specific internal energy\n",
      "pv = 287*(t+273.); \t\t\t#Nm/kg \t\t\t#p is pressure and v = specific volume\n",
      "\n",
      "\t\t\t\n",
      "# Calculations and Results\n",
      "Cv = poly(u);\n",
      "print \"Specific heat at constant volume,Cv = %.3f kJ/kgK\"%(Cv[0])\n",
      "\n",
      "h = u + pv*.001 \t\t\t#KJ/kg \t\t\t#enthalpy\n",
      "Cp = poly(h);\n",
      "print \"Specific heat at constant pressure,Cp = %.3f kJ/kgK\"%(Cp[0])\n",
      "\n",
      "# Note: Poly function gives different result then book has."
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "Specific heat at constant volume,Cv = 1.000 kJ/kgK\n",
        "Specific heat at constant pressure,Cp = 1.000 kJ/kgK\n"
       ]
      }
     ],
     "prompt_number": 6
    }
   ],
   "metadata": {}
  }
 ]
}