{ "metadata": { "name": "", "signature": "sha256:b7bd6954751643f92d25f5c6d00ec1b3a41e28e3d14c6105ad117f2707f6395b" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "heading", "level": 1, "metadata": {}, "source": [ "Chapter 4 Rotational motion of Rigid objects" ] }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 4.1 Page no 54" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#given\n", "w=4 #Angular velocity in rad/s\n", "m=(1,2,3,4) #Masses in kg from the figure 4.17 on page no.54 \n", "r=(2.5,1.5) #Centre position in m\n", "\n", "#Calculations\n", "I=(m[0]+m[1]+m[2]+m[3])*(r[0]**2+r[1]**2)\n", "KE=(1/2.0)*I*w**2\n", "\n", "#Output\n", "print\"The moment of inertia is \",I,\"kg.m**2\" \n", "print\"Kinetic energy of the system is \",KE,\"J\"\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The moment of inertia is 85.0 kg.m**2\n", "Kinetic energy of the system is 680.0 J\n" ] } ], "prompt_number": 1 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 4.2 Page no 55" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#given\n", "q=30 #Angle of inclination in degrees\n", "h=1 #Height in m\n", "\n", "#Calculations\n", "import math\n", "v=math.sqrt((10/7.0)*9.8*h)\n", "a=(5/7.0)*9.8*math.sin(q*3.14/180.0)\n", "\n", "#Output\n", "print\"Velocity and acceleration of the centre of mass of the sphere is \",round(v,2),\"m/s and \",round(a,1),\"m/s**2\"\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Velocity and acceleration of the centre of mass of the sphere is 3.74 m/s and 3.5 m/s**2\n" ] } ], "prompt_number": 3 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 4.3 Page no 55" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#given\n", "m=1.2 #Mass of the rod in kg\n", "l=0.8 #Length of the rod in m\n", "\n", "#Calculations\n", "import math\n", "T=2*3.14*math.sqrt((2*l)/(3.0*9.8))\n", "\n", "#Output\n", "print\"Period of oscillation is \",round(T,2),\"s\"\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Period of oscillation is 1.47 s\n" ] } ], "prompt_number": 4 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 4.4 Page no 55" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#given\n", "r=0.2 #Radius of uniform disc in m\n", "d=0.15 #Distance from the centre in m\n", "\n", "#Calculations\n", "import math\n", "T=2*3.14*math.sqrt((17*r)/(12.0*9.8))\n", "\n", "#Output\n", "print\"The period of oscillation is \",round(T,3),\"s\"\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The period of oscillation is 1.068 s\n" ] } ], "prompt_number": 5 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 4.5 Page no 55" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#given\n", "m=3 #Mass of the rotor in kg\n", "I=0.03 #Moment of inertia in kg.m^2\n", "d=0.25 #Distance of pivot from the centre in m\n", "p=30 #Precession in rpm\n", "\n", "#Calculations\n", "T=m*9.8*d\n", "w=(p*2*3.14)/60.0\n", "w1=(T/(I*w))\n", "\n", "#Output\n", "print\"Angular speed of rotation of the rotor is \",round(w1,0),\"rpm\"\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Angular speed of rotation of the rotor is 78.0 rpm\n" ] } ], "prompt_number": 6 } ], "metadata": {} } ] }