{ "metadata": { "name": "chapter 2 som.ipynb" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "heading", "level": 1, "metadata": {}, "source": [ "Chapter 2:Moment Of Inertia" ] }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Problem no 2.1,Page no.29" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "\n", "#Initilization of Variables\n", " \n", "#Rectangle-1\n", "b_1=10 #cm #width of Rectangle-1\n", "d_1=2 #cm #breadth of Rectangle-1\n", "a_1=40 #cm**2 #Area of Rectangle-1\n", "y_1=1 #cm #Distance of centroid-1\n", "\n", "#Rectangle-2\n", "b_2=2 #cm #width of Rectangle-2\n", "d_2=10 #cm #breadth of Rectangle-2\n", "a_2=20 #cm**2 #Area of rectangle-2\n", "y_2=7 #cm #Distance of centroid-2\n", "\n", "#Rectangle-3\n", "b_3=20 #cm #width of Rectangle-3\n", "d_3=2 #cm #breadth of Rectangle-3\n", "a_3=20 #cm**2 #Area of rectangle-3\n", "y_3=13 #cm #Distance of centroid-3\n", "\n", "\n", "\n", "#Calculation\n", "Y_bar=((a_1*y_1+a_2*y_2+a_3*y_3)*(a_1+a_2+a_3)**-1) #cm #centre of gravity of section\n", "\n", "Y_1=4.5 #cm #Distance of centroid of rectangle 1 to C.G\n", "Y_2=1.5 #cm #Distance of centroid of rectangle 2 to C.G\n", "Y_3=7.5 #cm #Distance of centroid of rectangle 3 to C.G\n", "\n", "I_x_x_1=b_1*d_1**3*12**-1+a_1*Y_1**2 #moment of inertia of rectangle 1 about centroidal x-x axis of the section\n", "I_x_x_2=b_2*d_2**3*12**-1+a_2*Y_2**2 #moment of inertia of rectangle 2 about centroidal x-x axis of the section\n", "I_x_x_3=b_3*d_3**3*12**-1+a_3*Y_3**2 #moment of inertia of rectangle 3 about centroidal x-x axis of the section\n", "I_x_x=I_x_x_1+I_x_x_2+I_x_x_3 #cm**4 \n", "\n", "#Result\n", "print\"Moment of Inertia of the section is\",round(I_x_x,2),\"cm**4\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Moment of Inertia of the section is 2166.67 cm**4\n" ] } ], "prompt_number": 10 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Problem no 2.2,Page no.31" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "\n", "#Initilization of Variables\n", "\n", "#Rectangle-1\n", "b_1=2 #cm #width of Rectangle-1\n", "d_1=12 #cm #breadth of Rectangle-1\n", "a_1=24 #cm**2 #Area of Rectangle-1\n", "y_1=6 #cm #Distance of centroid-1\n", "\n", "#Rectangle-2\n", "b_2=6 #cm #width of Rectangle-2\n", "d_2=2 #cm #breadth of Rectangle-2\n", "a_2=12 #cm**2 #Area of rectangle-2\n", "y_2=1 #cm #Distance of centroid-2\n", "\n", "#Rectangle-3\n", "b_3=2 #cm #width of Rectangle-3\n", "d_3=12 #cm #breadth of Rectangle-3\n", "a_3=24 #cm**2 #Area of rectangle-3\n", "y_3=6 #cm #Distance of centroid-3\n", "\n", "#Calculation\n", "Y_bar=((a_1*y_1+a_2*y_2+a_3*y_3)*(a_1+a_2+a_3)**-1) #cm #centre of gravity of section\n", "\n", "Y_1=6 #cm #Distance of centroid of rectangle 1 to base \n", "Y_2=1 #cm #Distance of centroid of rectangle 2 to base\n", "Y_3=6 #cm #Distance of centroid of rectangle 3 to base\n", "\n", "I_x_x_1=b_1*d_1**3*12**-1+a_1*Y_1**2 #moment of inertia of rectangle 1 about centroidal x-x axis of the section\n", "I_x_x_2=b_2*d_2**3*12**-1+a_2*Y_2**2 #moment of inertia of rectangle 2 about centroidal x-x axis of the section\n", "I_x_x_3=b_3*d_3**3*12**-1+a_3*Y_3**2 #moment of inertia of rectangle 3 about centroidal x-x axis of the section\n", "I_x_x=I_x_x_1+I_x_x_2+I_x_x_3 #cm**4 \n", "\n", "\n", "#Result\n", "print\"Moment of Inertia of the section is\",round(I_x_x,2),\"cm**4\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Moment of Inertia of the section is 2320.0 cm**4\n" ] } ], "prompt_number": 11 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Problem no2.3,Page no.32" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "\n", "#Initilization of Variables\n", "\n", "#Rectangle-1\n", "b_1=12 #cm #width of Rectangle-1\n", "d_1=2 #cm #breadth of Rectangle-1\n", "a_1=24 #cm**2 #Area of Rectangle-1\n", "y_1=1 #cm #Distance of centroid-1\n", "\n", "#Rectangle-2\n", "b_2=2 #cm #width of Rectangle-2\n", "d_2=6 #cm #breadthof Rectangle-2\n", "a_2=12 #cm**2 #Area of rectangle-2\n", "y_2=5 #cm #Distance of centroid-2\n", "\n", "#Rectangle-3\n", "b_3=5 #cm #width of Rectangle-3\n", "d_3=2 #cm #breadth of Rectangle-3\n", "a_3=10 #cm**2 #Area of rectangle-3\n", "y_3=9 #cm #Distance of centroid-3\n", "\n", "#Calculation\n", "Y_bar=((a_1*y_1+a_2*y_2+a_3*y_3)*(a_1+a_2+a_3)**-1) #cm #centre of gravity of section\n", "\n", "Y_1=2.78 #cm #Distance of centroid of rectangle 1 to C.G \n", "Y_2=1.22 #cm #Distance of centroid of rectangle 2 to C.G\n", "Y_3=5.22 #cm #Distance of centroid of rectangle 3 to C.G \n", "\n", "I_x_x_1=b_1*d_1**3*12**-1+a_1*Y_1**2 #moment of inertia of rectangle 1 about centroidal x-x axis of the section\n", "I_x_x_2=b_2*d_2**3*12**-1+a_2*Y_2**2 #moment of inertia of rectangle 2 about centroidal x-x axis of the section\n", "I_x_x_3=b_3*d_3**3*12**-1+a_3*Y_3**2 #moment of inertia of rectangle 3 about centroidal x-x axis of the section\n", "I_x_x=I_x_x_1+I_x_x_2+I_x_x_3 #cm**4 \n", "\n", "\n", "#Result\n", "print\"Moment of Inertia of the section is\",round(I_x_x,2),\"cm**4\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Moment of Inertia of the section is 523.16 cm**4\n" ] } ], "prompt_number": 12 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Problem no2.4,Page no.33" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "\n", "#Initilization of variables\n", "\n", "D=10 #cm #diameter of circle\n", "b=4 #cm #width of rectangle \n", "d=4 #cm #breadth of rectangle\n", "Y=1 #cm #Distance of centroid of rectangle 1 to C.G\n", "a=16 #cm**2 #area of rectangle\n", "\n", "#Calculations\n", "\n", "I_x_x_1=pi*64**-1*(D**4) #cm**4 #moment of inertia of circle about x-x axis\n", "I_x_x_2=b*d**3*12**-1+a*Y**2 #cm**4 #moment of inertia of rectangle about x-x axis\n", "I_x_x=I_x_x_1-I_x_x_2 #cm**4 #Total moment of inertia of the section\n", "\n", "#Result\n", "print\"Total moment of inertia of the section is\",round(I_x_x,2),\"cm**4\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Total moment of inertia of the section is 453.54 cm**4\n" ] } ], "prompt_number": 23 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Problem no 2.5,Page no.33" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "\n", "#Initilization of variables\n", "\n", "b_1=10 #cm #Breadth of the triangle\n", "h=9 #cm #Height of triangle\n", "b_2=2 #cm #width of rectangle\n", "d=3 #cm #Depth of rectangle\n", "\n", "#Triangle ABC-1\n", "a_1=45 #cm**2 #Area of triangle\n", "y_1=3 #cm #C.G of triangle\n", "\n", "#Rectanglar hole-2\n", "a_2=6 #cm**2 #Area of rectangle\n", "y_2=4.5 #cm #C.G of rectangle\n", "\n", "#Calculations\n", "\n", "#Using relations\n", "Y_bar=((a_1*y_1-a_2*y_2)*(a_1-a_2)**-1) #cm\n", "\n", "I_1=b_1*h**3*36**-1+a_1*(y_1-Y_bar)**2 #cm**4 #M.I of triangle ABC about x-x passing through C.G of section\n", "I_2=b_2*d**3*12**-1+a_2*(y_2-Y_bar)**2 #cm**4 #M.I of rectangular hole about x-x passing through C.G of section\n", "I=I_1-I_2 #cm**4 #M.I of whole section about x-x passing through the C.G \n", "\n", "I_3=b_1*h**3*12**-1 #cm**4 #M.I of triangle ABC about the base BC\n", "I_4=b_2*d**3*12**-1+a_2*y_2**2 #cm**4 #M.I of Rectangular hole about the base BC\n", "\n", "I_5=I_3-I_4 #cm**4 #M.I of the whole section about the base BC\n", "\n", "#Result\n", "print\"M.I of whole section about x-x passing through the C.G\",round(I,2),\"cm**4\"\n", "print\"M.I of the whole section about the base BC is\",round(I_5,2),\"cm**4\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "M.I of whole section about x-x passing through the C.G 182.42 cm**4\n", "M.I of the whole section about the base BC is 481.5 cm**4\n" ] } ], "prompt_number": 39 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Problem no2.6,Page no.34" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "\n", "#Initilization of variables\n", "\n", "\n", "#Notifications has been changed as per requirement\n", "\n", "\n", "h=8 #cm #height of triangle\n", "b=8 #cm #breadth of triangle or diameter semicircle\n", "d=4 #cm #diameter of circle enclosed\n", "\n", "#Calculations\n", "\n", "I_1=b*h**3*12**-1 #cm #moment of inertia of the triangle ABC about the axis AB\n", "I_2=pi*b**4*128**-1 #cm ##moment of inertia of the semicircle about the axis AB\n", "I_3=pi*d**4*64**-1 #cm #moment of inertia of circle about the circle about the axis\n", "\n", "I=I_1+I_2-I_3 #cm #Moment of Inertia of the shaded area about the axia AB\n", "\n", "#Result\n", "print\"Moment of Inertia of the shaded area is\",round(I,2),\"cm\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Moment of Inertia of the shaded area is 429.3 cm\n" ] } ], "prompt_number": 30 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Problem no.2.12,Page no.38" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "\n", "#Initilization of variables\n", "\n", "#Rectangle\n", "a_1=600 #cm**2 #Area of the Rectangle\n", "y_1=15 #cm #C.G of Rectangle\n", "b=20 #cm #width of rectangle\n", "d=30 #cm #depth of rectangle\n", "D=15 #cm #Diameter of circle\n", "\n", "#Circle\n", "a_2=176.7 #cm**2 #Area of the circle\n", "y_2=20 #cm #C.G of the circle\n", " \n", "#Calculation\n", "\n", "Y_bar=((a_1*y_1-a_2*y_2)*(a_1-a_2)**-1) #cm #Distance of C.G From the AB\n", "Y_bar_1=2.1 #cm\n", "Y_bar_2=7.1 #cm\n", "\n", "I_1=b*d**3*12**-1 #cm**4 #M.I of the rectangle about its C.G and parallel to x-x axis\n", "I_2=I_1+a_1*Y_bar_1**2\n", "I_3=pi*D**4*64**-1+a_2*Y_bar_2**2 #cm**4 #M.I of circular section about x-x axis\n", "\n", "I=I_2-I_3 #cm**4 #M.I of the section about x-x axis\n", "\n", "#Result\n", "print\"M.I of the section about x-x axis\",round(I,2),\"cm**4\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "M.I of the section about x-x axis 36253.5 cm**4\n" ] } ], "prompt_number": 50 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Problem no.2.13,Page no.38" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "\n", "#Initilization of variables\n", "\n", "d=90 #cm #Diameter of grindstone\n", "t=10 #cm #thickness of grindstone\n", "rho=0.0026 #Kg/cm**3 #Density\n", "\n", "#calculations\n", "\n", "#M=Mass of grindstone=Volume *Density=Area*Thickness*Density\n", "M=pi*4**-1*d**2*t*rho #Kg \n", "R=d*2**-1 #cm #radius\n", "I_g=M*R**2*2**-1 #Kg*m**2\n", "\n", "k=R*(2**0.5)**-1 #cm #Radius of gyration\n", "\n", "#Result\n", "print\"Radius of gyration is\",round(k,2),\"cm\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Radius of gyration is 31.82 cm\n" ] } ], "prompt_number": 6 } ], "metadata": {} } ] }