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{

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  "name": "",

  "signature": "sha256:83169fd272ce864306940c4a49b0d63f096c19015d841f59df75135834323538"

 },

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 "nbformat_minor": 0,

 "worksheets": [

  {

   "cells": [

    {

     "cell_type": "heading",

     "level": 1,

     "metadata": {},

     "source": [

      "Chapter07: Motion in a Circle"

     ]

    },

    {

     "cell_type": "heading",

     "level": 2,

     "metadata": {},

     "source": [

      "Ex7.1:pg-208"

     ]

    },

    {

     "cell_type": "code",

     "collapsed": false,

     "input": [

      "  #Example 7_1\n",

      " \n",

      "  \n",

      "  #To convert angles to radians and revolutions\n",

      "theta=70.0      #units in degrees\n",

      "deg=360.0     #units in degrees\n",

      "rad=theta*2*math.pi/deg      #units in radians\n",

      "rev=1     #units in revolution\n",

      "rev=theta*rev/deg       #units in revolution\n",

      "print \" 70 degrees in radians is \",round(rad,2),\"radians \\n 70 degrees in revolutions it is \",round(rev,3),\" revolutions\"\n"

     ],

     "language": "python",

     "metadata": {},

     "outputs": [

      {

       "output_type": "stream",

       "stream": "stdout",

       "text": [

        " 70 degrees in radians is  1.22 radians \n",

        " 70 degrees in revolutions it is  0.194  revolutions\n"

       ]

      }

     ],

     "prompt_number": 16

    },

    {

     "cell_type": "heading",

     "level": 2,

     "metadata": {},

     "source": [

      "Ex7.2:pg-209"

     ]

    },

    {

     "cell_type": "code",

     "collapsed": false,

     "input": [

      "  #Example 7_2\n",

      " \n",

      "  \n",

      "#To find average angular velocity\n",

      "theta=1800.0     #units in rev\n",

      "t=60.0      #units in sec\n",

      "w=(theta/t)     #units in rev/sec\n",

      "w=w*(2*math.pi)      #units in rad/sec\n",

      "print \"Average angular velocity is w=\",round(w),\" rad/sec\"\n"

     ],

     "language": "python",

     "metadata": {},

     "outputs": [

      {

       "output_type": "stream",

       "stream": "stdout",

       "text": [

        "Average angular velocity is w= 188.0  rad/sec\n"

       ]

      }

     ],

     "prompt_number": 17

    },

    {

     "cell_type": "heading",

     "level": 2,

     "metadata": {},

     "source": [

      "Ex7.3:pg-210"

     ]

    },

    {

     "cell_type": "code",

     "collapsed": false,

     "input": [

      "  #Example 7_3\n",

      " \n",

      "  \n",

      "  #To find average angular acceleration\n",

      "wf=240.0     #units in rev/sec\n",

      "w0=0      #units in rev/sec\n",

      "t=2.0     #units in minutes\n",

      "t=t*60     #units in sec\n",

      "alpha=(wf-w0)/t      #units in rev/sec**2\n",

      "print \"Average angular acceleration is alpha=\",round(alpha),\" rev/sec**2\"\n"

     ],

     "language": "python",

     "metadata": {},

     "outputs": [

      {

       "output_type": "stream",

       "stream": "stdout",

       "text": [

        "Average angular acceleration is alpha= 2.0  rev/sec**2\n"

       ]

      }

     ],

     "prompt_number": 18

    },

    {

     "cell_type": "heading",

     "level": 2,

     "metadata": {},

     "source": [

      "Ex7.4:pg-212"

     ]

    },

    {

     "cell_type": "code",

     "collapsed": false,

     "input": [

      "  #Example 7_4\n",

      " \n",

      "  \n",

      "#To find out how many revolutions does it turn before rest\n",

      "wf=0     #units in rev/sec\n",

      "w0=3      #units in rev/sec\n",

      "t=18     #units in sec\n",

      "alpha=(wf-w0)/t      #units in rev/sec**2\n",

      "theta=(w0*t)+0.5*(alpha*t**2)         #units in rev\n",

      "print \"Number of revolutions does it turn before rest is theta=\",round(theta),\" rev\"\n"

     ],

     "language": "python",

     "metadata": {},

     "outputs": [

      {

       "output_type": "stream",

       "stream": "stdout",

       "text": [

        "Number of revolutions does it turn before rest is theta= -108.0  rev\n"

       ]

      }

     ],

     "prompt_number": 19

    },

    {

     "cell_type": "heading",

     "level": 2,

     "metadata": {},

     "source": [

      "Ex7.5:pg-212"

     ]

    },

    {

     "cell_type": "code",

     "collapsed": false,

     "input": [

      "  #Example 7_5\n",

      " \n",

      "  \n",

      "  #To find the angular acceleration and angular velocity of one wheel\n",

      "vtf=20.0     #units in meters/sec\n",

      "r=0.4      #units in meters\n",

      "wf=vtf/r     #units in rad/sec\n",

      "vf=20.0     #units in meters/sec\n",

      "v0=0      #units in meters/sec**2\n",

      "t=9.0     #units in sec\n",

      "a=(vf-v0)/t     #units in meters/sec**2\n",

      "alpha=a/r       #units in rad/sec**2\n",

      "print \"Angular accelertion is a=\",round(a,2),\" meters/sec**2\\n\"\n",

      "print \"Angular velocity is alpha=\",round(alpha,2),\" rad/sec**2\"\n"

     ],

     "language": "python",

     "metadata": {},

     "outputs": [

      {

       "output_type": "stream",

       "stream": "stdout",

       "text": [

        "Angular accelertion is a= 2.22  meters/sec**2\n",

        "\n",

        "Angular velocity is alpha= 5.56  rad/sec**2\n"

       ]

      }

     ],

     "prompt_number": 20

    },

    {

     "cell_type": "heading",

     "level": 2,

     "metadata": {},

     "source": [

      "Ex7.6:pg-213"

     ]

    },

    {

     "cell_type": "code",

     "collapsed": false,

     "input": [

      "  #Example 7_6\n",

      " \n",

      "  \n",

      "  #To find out the rotation rate\n",

      "at=8.6     #units in meters/sec**2\n",

      "r=0.2      #units in meters\n",

      "alpha=at/r      #units in rad/sec**2\n",

      "t=3     #units in sec\n",

      "wf=alpha*t     #units in rad/sec\n",

      "print \"The rotation rate is wf=\",round(wf),\" rad/sec\"\n"

     ],

     "language": "python",

     "metadata": {},

     "outputs": [

      {

       "output_type": "stream",

       "stream": "stdout",

       "text": [

        "The rotation rate is wf= 129.0  rad/sec\n"

       ]

      }

     ],

     "prompt_number": 22

    },

    {

     "cell_type": "heading",

     "level": 2,

     "metadata": {},

     "source": [

      "Ex7.7:pg-215"

     ]

    },

    {

     "cell_type": "code",

     "collapsed": false,

     "input": [

      "  #Example 7_7\n",

      " \n",

      "  \n",

      "  #To calculate how large a horizontal force must the pavement exert\n",

      "m=1200.0     #units in Kg\n",

      "v=8.0     #units in meters/sec\n",

      "r=9      #units in meters\n",

      "F=(m*v**2)/r         #units in Newtons\n",

      "print \"The horizontal force must the pavement exerts is F=\",round(F),\" Newtons\"\n",

      "  #In text book the answer is printed wrong as F=8530 N but the correct answer is 8533 N\n"

     ],

     "language": "python",

     "metadata": {},

     "outputs": [

      {

       "output_type": "stream",

       "stream": "stdout",

       "text": [

        "The horizontal force must the pavement exerts is F= 8533.0  Newtons\n"

       ]

      }

     ],

     "prompt_number": 25

    },

    {

     "cell_type": "heading",

     "level": 2,

     "metadata": {},

     "source": [

      "Ex7.9:pg-220"

     ]

    },

    {

     "cell_type": "code",

     "collapsed": false,

     "input": [

      "  #Example 7_9\n",

      " \n",

      "  \n",

      "  #To find out the angle where it should be banked\n",

      "v=25     #units in meters/sec\n",

      "r=60     #units in meters\n",

      "g=9.8     #units in meters/sec**2\n",

      "tantheta=v**2/(r*g)        #units in radians\n",

      "theta=math.atan(tantheta)*180/math.pi\n",

      "print \"The angle where it should be banked is theta=\",round(theta),\" degrees\",\n"

     ],

     "language": "python",

     "metadata": {},

     "outputs": [

      {

       "output_type": "stream",

       "stream": "stdout",

       "text": [

        "The angle where it should be banked is theta= 47.0  degrees\n"

       ]

      }

     ],

     "prompt_number": 26

    },

    {

     "cell_type": "heading",

     "level": 2,

     "metadata": {},

     "source": [

      "Ex7.10:pg-220"

     ]

    },

    {

     "cell_type": "code",

     "collapsed": false,

     "input": [

      "  #Example 7_10\n",

      " \n",

      "  \n",

      "  #To find out the ratio of F/W\n",

      "G=6.67*10**-11     #units in Newton meter**2/Kg**2\n",

      "m1=0.0080      #units in Kgs\n",

      "m2=0.0080      #units in Kgs\n",

      "r=2     #units in Meters\n",

      "F=(G*m1*m2)/r**2      #units in Newtons\n",

      "m=m1      #units in Kgs\n",

      "g=9.8     #units in meter/sec**2\n",

      "W=m*g     #units in Newtons\n",

      "F_W=F/W\n",

      "print \"The F/W Ratio is=\",round(F_W,16)\n"

     ],

     "language": "python",

     "metadata": {},

     "outputs": [

      {

       "output_type": "stream",

       "stream": "stdout",

       "text": [

        "The F/W Ratio is= 1.36e-14\n"

       ]

      }

     ],

     "prompt_number": 28

    },

    {

     "cell_type": "heading",

     "level": 2,

     "metadata": {},

     "source": [

      "Ex7.11:pg-221"

     ]

    },

    {

     "cell_type": "code",

     "collapsed": false,

     "input": [

      "  #Example 7_11\n",

      " \n",

      "  \n",

      "  #To find the mass of the sun\n",

      "t=3.15*10**7     #units in sec\n",

      "r=1.5*10**11     #units in meters\n",

      "v=(2*math.pi*r)/t     #units in meters/sec\n",

      "G=6.67*10**-11     #units in Newtons\n",

      "ms=(v**2*r)/G           #Units in Kg\n",

      "print \"The mass of the sun is Ms=\",round(ms,-28),\"Kg\"\n"

     ],

     "language": "python",

     "metadata": {},

     "outputs": [

      {

       "output_type": "stream",

       "stream": "stdout",

       "text": [

        "The mass of the sun is Ms= 2.01e+30 Kg\n"

       ]

      }

     ],

     "prompt_number": 32

    },

    {

     "cell_type": "heading",

     "level": 2,

     "metadata": {},

     "source": [

      "Ex7.12:pg-222"

     ]

    },

    {

     "cell_type": "code",

     "collapsed": false,

     "input": [

      "  #Example 7_12\n",

      " \n",

      "  \n",

      "  #To findout the orbital radius and its speed\n",

      "G=6.67*10**-11     #units in Newtons\n",

      "me=5.98*10**24     #units in Kg\n",

      "t=86400.0    #units in sec\n",

      "r=((G*me*t**2)/(4*math.pi**2))**(1/3.0)\n",

      "print \"The orbital radius is r= \",round(r),\" meters\\n\"\n",

      "v=(2*math.pi*r)/t      #units in meters/sec\n",

      "print \"The orbital speed is v=\",round(v),\" meters/sec\"\n",

      "  #in textbook the answer is printed wrong as v=3070 m/sec but the correct answer is v=3073 m/sec\n"

     ],

     "language": "python",

     "metadata": {},

     "outputs": [

      {

       "output_type": "stream",

       "stream": "stdout",

       "text": [

        "The orbital radius is r=  42250474.0  meters\n",

        "\n",

        "The orbital speed is v= 3073.0  meters/sec\n"

       ]

      }

     ],

     "prompt_number": 34

    }

   ],

   "metadata": {}

  }

 ]

}