{ "cells": [ { "cell_type": "markdown", "metadata": {}, "source": [ "# Chapter 1-INTRODUCTION TO MECHANICS OF SOLIDS " ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "# example1.1 Page number 10\n" ] }, { "cell_type": "code", "execution_count": 1, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ " The resultant velocity : 21.54 km/hour\n", "68.2 °\n" ] } ], "source": [ "#downstream direction as x\n", "#direction across river as y\n", "\n", "from math import sqrt,atan,pi\n", "\n", "#variable declaration\n", "\n", "Vx= 8 #velocity of stream, km/hour\n", "Vy=float(20) #velocity of boat,km/hour\n", "\n", "V=sqrt(pow(Vx,2)+pow(Vy,2)) #resultant velocity, km/hour\n", "theta=Vy/Vx\n", "\n", "alpha= atan(theta)*180/pi #angle, degrees \n", "\n", "print \" The resultant velocity :\",round(V,2),\"km/hour\"\n", "print round(alpha,2),\"°\"\n", "\n" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "# example 1.2 Page number 10" ] }, { "cell_type": "code", "execution_count": 2, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "10.0 KN (to the left)\n", "17.32 KN (downward)\n" ] } ], "source": [ "\n", "\n", "\n", "#components of force in horizontal and vertical components. \n", "from math import cos,sin,pi\n", "#variable declaration\n", "\n", "F= 20 #force in wire, KN\n", "\n", "#calculations\n", "Fx= F*cos(60*pi/180) \n", "Fy= F*sin(60*pi/180)\n", "\n", "print round(Fx,2),\"KN\" ,\"(to the left)\"\n", "print round(Fy,2), \"KN\" ,\"(downward)\"\n", "\n", "\n" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "# example 1.3 Page number 11" ] }, { "cell_type": "code", "execution_count": 3, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "Component normal to the plane : 9.4 KN\n", "Component parallel to the plane : 3.42 KN\n" ] } ], "source": [ "\n", "\n", " #The plane makes an angle of 20° to the horizontal. Hence the normal to the plane makes an angles of 70° to the horizontal i.e., 20° to the vertical\n", "from math import cos,sin,pi\n", "#variable declaration\n", "W= 10 # black weighing, KN\n", "\n", "#calculations\n", "\n", "Nor= W*cos(20*pi/180) #Component normal to the plane\n", "para= W*sin(20*pi/180) #Component parallel to the plane\n", "\n", "print \"Component normal to the plane :\",round(Nor,2),\"KN\"\n", "print \"Component parallel to the plane :\",round(para,2) , \"KN\"\n", "\n", "\n", "\n" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "# example 1.4 Page number 11" ] }, { "cell_type": "code", "execution_count": 4, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "F1= 100.0 N\n", "F2= 200.0 N\n", "theta= 63.9 °\n" ] } ], "source": [ "\n", "\n", "#Let the magnitude of the smaller force be F. Hence the magnitude of the larger force is 2F\n", "\n", "from math import pi,sqrt, acos\n", "#variable declaration\n", "R1=260 #resultant of two forces,N\n", "R2=float(180) #resultant of two forces if larger force is reversed,N\n", "\n", "\n", "\n", "#calculations\n", "\n", "F=sqrt((pow(R1,2)+pow(R2,2))/10)\n", "F1=F\n", "F2=2*F\n", "theta=acos((pow(R1,2)-pow(F1,2)-pow(F2,2))/(2*F1*F2))*180/pi\n", "\n", "print \"F1=\",F1,\"N\"\n", "print \"F2=\",F2,\"N\"\n", "print \"theta=\",round(theta,1),\"°\"\n", "\n", "\n" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "# example 1.5 Page number 12" ] }, { "cell_type": "code", "execution_count": 5, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "F1= 326.35 N\n", "F2= 223.24 N\n" ] } ], "source": [ "\n", "\n", "#Let ?ABC be the triangle of forces drawn to some scale\n", "#Two forces F1 and F2 are acting at point A\n", "#angle in degrees '°'\n", "\n", "from math import sin,pi\n", " \n", "#variabble declaration\n", "cnv=pi/180\n", "\n", "BAC = 20*cnv #Resultant R makes angle with F1 \n", " \n", "ABC = 130*cnv \n", "\n", "ACB = 30*cnv \n", "\n", "R = 500 #resultant force,N\n", "\n", "#calculations\n", "#sinerule\n", "\n", "F1=R*sin(ACB)/sin(ABC)\n", "F2=R*sin(BAC)/sin(ABC)\n", "\n", "print \"F1=\",round(F1,2),\"N\"\n", "print \"F2=\",round(F2,2),\"N\"\n", "\n", "\n" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "# example 1.6 Page number 12" ] }, { "cell_type": "code", "execution_count": 6, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "theta= 78.13 °\n", "alpha= 29.29 °\n" ] } ], "source": [ "\n", "\n", "#Let ABC be the triangle of forces,'theta' be the angle between F1 and F2, and 'alpha' be the angle between resultant and F1 \n", "\n", "from math import sin,acos,asin,pi\n", "\n", "#variable declaration\n", "cnv= 180/pi\n", "F1=float(400) #all forces are in newtons,'N'\n", "F2=float(260)\n", "R=float(520)\n", "\n", "#calculations\n", "\n", "theta=acos((pow(R,2)-pow(F1,2)-pow(F2,2))/(2*F1*F2))*cnv\n", "\n", "alpha=asin(F2*sin(theta*pi/180)/R)*cnv\n", "\n", "print\"theta=\",round(theta,2),\"°\"\n", "print \"alpha=\",round(alpha,2),\"°\"\n", "\n" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "# example 1.7 Page number 13" ] }, { "cell_type": "code", "execution_count": 7, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "horizontal component= 2814.2 N\n", "Vertical component = 1039.2 N\n", "Component along crank = 507.1 N\n", "Component normal to crank= 2956.8 N\n" ] } ], "source": [ "\n", "\n", "#The force of 3000 N acts along line AB. Let AB make angle alpha with horizontal.\n", "\n", "from math import cos,sin,pi,asin,acos\n", "\n", "#variable declaration\n", "F=3000 #force in newtons,'N'\n", "BC=80 #length of crank BC, 'mm'\n", "AB=200 #length of connecting rod AB ,'mm'\n", "theta=60*pi/180 #angle b/w BC & AC\n", "\n", "#calculations\n", "\n", "alpha=asin(BC*sin(theta)/200)*180/pi\n", "\n", "HC=F*cos(alpha*pi/180) #Horizontal component \n", "VC= F*sin(alpha*pi/180) #Vertical component \n", "\n", "#Components along and normal to crank\n", "#The force makes angle alpha + 60 with crank.\n", "alpha2=alpha+60\n", "CAC=F*cos(alpha2*pi/180) # Component along crank \n", "CNC= F*sin(alpha2*pi/180) #Component normal to crank \n", "\n", "\n", "print \"horizontal component=\",round(HC,1),\"N\"\n", "print \"Vertical component = \",round(VC,1),\"N\"\n", "print \"Component along crank =\",round(CAC,1),\"N\"\n", "print \"Component normal to crank=\",round(CNC,1),\"N\"" ] } ], "metadata": { "anaconda-cloud": {}, "kernelspec": { "display_name": "Python [Root]", "language": "python", "name": "Python [Root]" }, "language_info": { "codemirror_mode": { "name": "ipython", "version": 2 }, "file_extension": ".py", "mimetype": "text/x-python", "name": "python", "nbconvert_exporter": "python", "pygments_lexer": "ipython2", "version": "2.7.12" } }, "nbformat": 4, "nbformat_minor": 0 }