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	   "source": [
       "# Chapter 3: Heat and Work"
	   ]
	},
{
		   "cell_type": "markdown",
		   "metadata": {},
		   "source": [
			"## Example 3.1: constant_pressure_work_done.sce"
		   ]
		  },
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"clc\n",
"//solution\n",
"//initialization of variables\n",
"m=1               // mass in kg\n",
"x=20/100         //quality of steam\n",
"P=200          //constant pressure in kPa\n",
"T1=100          //temperature intitial in degree centigrade\n",
"T2=400          //temperature final in degree centigrade\n",
"\n",
"// first we find initial volume v1 and final volume v2\n",
"\n",
"// using table C.2\n",
"vf=0.001061 // specific volume of saturated liquid in m^3 per kg \n",
"vg=0.8857  //specific volume of saturated vapour in m^3 per kg \n",
"\n",
"v1=vf+x*(vg-vf);\n",
"\n",
"v2=1.549   //specific volume of steam in m^3 per kg at T2=400*C and P2=0.2MPa\n",
"// now calculate work\n",
"W=m*P*(v2-v1);   //work done in constant pressure process\n",
"printf('Work done is %.1f kJ',W) // work is in kJ as pressure was in kPa"
   ]
   }
,
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		   "cell_type": "markdown",
		   "metadata": {},
		   "source": [
			"## Example 3.2: 110mm_diameter_cylinder_work_done.sce"
		   ]
		  },
  {
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"clc\n",
"//initialization of variables\n",
"D=110/1000 // diameter of cylinder in m\n",
"V1=100e-6 // initial volume@ state 1 in m^3\n",
"T1=60 // initial temp @ state 1 in *C\n",
"T2=200 // final temo @ state 2 in *C\n",
"M=50 // weight of piston in kg\n",
"g=9.81 // gravitational accleration in m/sec^2\n",
"Patm=100000 // atmospheric pressure in Pa\n",
"A=%pi*(D^2)/4 // area of piston in m^2\n",
"\n",
"// BALANCING THE FORCES To GET PRESSURE P\n",
"// M.g=P.A-Patm\n",
"P=Patm+(M*g/A) // atm pressure is added to get absolute pressure\n",
"\n",
"v1=0.001017 // specific volume at 60*C and 0.15Mpa pressure\n",
"m=V1/v1; // mass of water in kg\n",
"\n",
"// find volume at state 2 \n",
"v2=1.444 // specific volume of steam at 200*C and 0.15 MPa\n",
"V2=m*v2// final volume in m^3\n",
"\n",
"W=P*(V2-V1)/1000; // work done divided by 1000 to get in kJ\n",
"printf('The work done is %.1f kJ',W)\n",
"\n",
"\n",
"\n",
"\n",
""
   ]
   }
,
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		   "cell_type": "markdown",
		   "metadata": {},
		   "source": [
			"## Example 3.3: isothermal_work_by_the_ideal_gas.sce"
		   ]
		  },
  {
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	   "execution_count": null,
	   "metadata": {
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"clc\n",
"//initialization of variables\n",
"P1=200      // initial pressure in kPa\n",
"V1=2        //initial volume in m^3\n",
"P2=100     //final pressure in kPa\n",
"C=P1*V1// isothermal process i.e P.V=constant\n",
"//  find final volume \n",
"V2=P1*V1/P2 // final volume by P1.V1=P2.V2\n",
"\n",
"function[p]=pressure(v) // expressing pressure as function of volume\n",
"    p=C/v;\n",
"endfunction\n",
" \n",
"W=integrate('C/v','v',V1,V2) //itegrating over volume to get work\n",
"printf('The Work done by gas is %.0f kJ',W) // answer is approximated in textbook"
   ]
   }
,
{
		   "cell_type": "markdown",
		   "metadata": {},
		   "source": [
			"## Example 3.4: A_100_kg_mass_drops_3_m.sce"
		   ]
		  },
  {
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	   "execution_count": null,
	   "metadata": {
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"clc//\n",
"//initialization of variables\n",
"M=100 // mass in kg\n",
"d=3 // depth by which mass drops in m\n",
"V=0.002 // increased volume in m^3\n",
"g=9.81 // gravitational accleration in m/sec^2\n",
"Pgauge=100*1000// gauge pressure in N/m\n",
"Patm =100*1000 // atmospheric pressure in N/m\n",
"P=Pgauge+Patm // to get absolute pressure\n",
"\n",
"//calculate work done by paddle wheel\n",
"Wpaddlewheel=(-M*g*d) // work is negative as it is done on the system\n",
"\n",
"//calculate work done on piston it \n",
"Wboundary=P*V // area mulitiplied by height is volume thus W=P.V \n",
"//net work\n",
"Wnet=Wpaddlewheel+Wboundary; // Work in joule as SI units are used\n",
"printf('The Net Work done is '+string(Wnet)+' J')\n",
"// in textbook answer is 2450 J which is when we assume g=9.80 "
   ]
   }
,
{
		   "cell_type": "markdown",
		   "metadata": {},
		   "source": [
			"## Example 3.5: drive_shaft_in_an_automobile_delivers.sce"
		   ]
		  },
  {
"cell_type": "code",
	   "execution_count": null,
	   "metadata": {
	    "collapsed": true
	   },
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"source": [
"clc\n",
"// initialization of variables\n",
"T=100 // torque of shaft in N.m\n",
"N=3000 // rotation speed in rpm\n",
"omega=(N*2*%pi/60) // angular velocity in rad/sec\n",
"// calculation of power\n",
"Wdot=(T*omega); // power is work done per unit time\n",
"printf('Power transmitted is %.1f hp',Wdot/746)  // divided by 746 to convert W into hp\n",
"//answer is approximated in textbook"
   ]
   }
,
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		   "cell_type": "markdown",
		   "metadata": {},
		   "source": [
			"## Example 3.6: Heat_supplied_at_constant_pressure.sce"
		   ]
		  },
  {
"cell_type": "code",
	   "execution_count": null,
	   "metadata": {
	    "collapsed": true
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"source": [
"clc\n",
"// initialization of variables\n",
"D=10/100  //diameter of cylinder in m\n",
"d=50/1000  //compression in spring in m\n",
"Patm=100000    // atmospheric pressure in Pa\n",
"K=10*1000   // spring constant converted in  N/m\n",
"w=50*9.81  // weight of piston in Newton =mass*gravitational acceleration\n",
"\n",
"// find the initial pressure in cylinder by force balance\n",
"A=(%pi*D^2)/4; // area of piston\n",
"P1=((Patm*A)+w)/A;      // balancing forces on piston P1.A=Patm.A+W\n",
"\n",
"// work done by air to raise the piston for 50mm if spring not present\n",
"Wgas=P1*A*d; // pressure*area= force and Work = Force* displacement\n",
"\n",
"// work done on spring to compress\n",
"Wspring=(K*d^2)/2; // Work in j\n",
"\n",
"// now total work done by air is sum of two works\n",
"Wnet=Wgas+Wspring; // Work in j\n",
"\n",
"printf('The net work done by air is %.2f J',Wnet)\n",
"//The answer is approximated in textbook but here it is precise"
   ]
   }
,
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		   "cell_type": "markdown",
		   "metadata": {},
		   "source": [
			"## Example 3.7: non_quasiequilibrium_process.sce"
		   ]
		  },
  {
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	   "execution_count": null,
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"clc\n",
"// variable initialization\n",
"\n",
"d=2   //distance travelled by weight in m\n",
"m=50  // mass of weight in kg\n",
"g=9.8  // gravitaional acceleration in m/sec^2\n",
"\n",
"// calculation of work in non-quasiequilibrium process\n",
"W=m*g*d;// work in joules\n",
"\n",
"// the work done must be transferred as heat\n",
"Q=W;\n",
"\n",
"printf('The heat that must transfer is '+string(Q)+' Joules')"
   ]
   }
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