{ "metadata": { "name": "", "signature": "sha256:c5834020c85eb4ee9dd0f62630cfe11c8ed3ce693f7ae9cc407ce5e3a8a74085" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "heading", "level": 1, "metadata": {}, "source": [ "Chapter 7 : Velocity in Mechanisms (Relative Velocity Method)" ] }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 7.1 Page No : 148" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math \n", "\n", "# Variables:\n", "NBA = 120. \t\t\t#rpm\n", "AB = 40./1000\n", "CD = 80./1000 \t\t\t#m\n", "\n", "#Solution:\n", "#Refer Fig. 7.7\n", "#Calculating the angular velocity of the crank AB\n", "omegaBA = 2*math.pi*NBA/60 \t\t\t#rad/s\n", "#Calculating the velocity of B with respect to A\n", "vBA = omegaBA*AB \t\t\t#m/s\n", "vB = vBA\n", "#By measurement from the velocity diagram Fig. 7.7(b)\n", "vCD = 0.385 \t\t\t#m/s\n", "vC = vCD\n", "#Calculating the angular velocity of link CD\n", "omegaCD = vCD/CD \t\t\t#rad/s\n", "\n", "#Results:\n", "print \" The angular velocity of link CD omegaCD = %.1f rad/s clockwise about D.\"%(omegaCD)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ " The angular velocity of link CD omegaCD = 4.8 rad/s clockwise about D.\n" ] } ], "prompt_number": 1 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 7.2 Page No : 148" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math \n", "\n", "# Variables:\n", "NBO = 180. \t\t\t#rpm\n", "OB = 0.5\n", "PB = 2.\n", "dO = 50./1000\n", "dB = 60./1000\n", "dC = 30./1000 \t\t\t#m\n", "\n", "#Solution:\n", "#Refer Fig. 7.8\n", "#Calculating the angular velocity of the crank BO\n", "omegaBO = 2*math.pi*NBO/60 \t\t\t#rad/s\n", "#Calculating the linear velocity of B with respect to O\n", "vBO = omegaBO*OB \t\t\t#m/s\n", "vB = vBO\n", "#By measurement from the velocity diagram Fig. 7.8(b)\n", "vP = 8.15\n", "vPB = 6.8\n", "vE = 8.5\n", "bg = 5.\n", "bp = vPB\n", "vG = 8. \t\t\t#m/s\n", "#Calculating the angular velocity of the connecting rod PB\n", "omegaPB = vPB/PB \t\t\t#rad/s\n", "#Calculating the velocity of rubbing at the pin of crank-shaft\n", "vCS = dO/2*omegaBO \t\t\t#Velocity of rubbing at the pin of crank-shaft m/s\n", "#Calculating the velocity of rubbing at the pin of crank\n", "vC = dB/2*(omegaBO+omegaPB) \t\t\t#Velocity of rubbing at the pin of crank m/s\n", "#Calculating the velocity of rubbing at the pin of cross-head\n", "vPCH = dC/2*omegaPB \t\t\t#Velocity of rubbing at the pin of cross-head m/s\n", "#Calculating the position of point G on the connecting rod\n", "BG = bg/bp*PB \t\t\t#m\n", "\n", "#Results:\n", "print \" The velocity of piston P vP = %.2f m/s.\"%(vP)\n", "print \" The angular velocity of connecting rod omegaPB = %.1f rad/s anticlockwise.\"%(omegaPB)\n", "print \" The velocity of point E on the connecting rod vE = %.1f m/s.\"%(vE)\n", "print \" The velocity of rubbing at the pin of crank-shaft is %.2f m/s.\"%(vCS)\n", "print \" The velocity of rubbing at the pin of crank is %.4f m/s.\"%(vC)\n", "print \" The velocity of rubbing at the pin of cross-head is %.3f m/s.\"%(vPCH)\n", "print \" The position of point G on the connecting rod BG = %.2f m.\"%(BG)\n", "print \" The linear velocity of point G vG = %d m/s.\"%(vG)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ " The velocity of piston P vP = 8.15 m/s.\n", " The angular velocity of connecting rod omegaPB = 3.4 rad/s anticlockwise.\n", " The velocity of point E on the connecting rod vE = 8.5 m/s.\n", " The velocity of rubbing at the pin of crank-shaft is 0.47 m/s.\n", " The velocity of rubbing at the pin of crank is 0.6675 m/s.\n", " The velocity of rubbing at the pin of cross-head is 0.051 m/s.\n", " The position of point G on the connecting rod BG = 1.47 m.\n", " The linear velocity of point G vG = 8 m/s.\n" ] } ], "prompt_number": 2 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 7.3 Page No : 150" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math \n", "\n", "# Variables:\n", "NAO = 600. \t\t\t#rpm\n", "OA = 28./1000 #m\n", "BD = 46./1000 \t\t#m\n", "\n", "#Solution:\n", "#Refer Fig. 7.10\n", "#Calculating the angular velocity of crank AO\n", "omegaAO = 2*math.pi*NAO/60 \t\t\t#rad/s\n", "#Calculating the velocity of A with respect to O\n", "vAO = omegaAO*OA \t\t\t#m/s\n", "vA = vAO\n", "#By measurement from the velocity diagram Fig. 7.10(b)\n", "vD = 1.6\n", "vDB = 1.7 \t\t\t#m/s\n", "#Calculating the angular velocity of D with respect to B\n", "omegaBD = vDB/BD \t\t\t#rad/s\n", "\n", "#Results:\n", "print \" The velocity of the slider D vD = %.1f m/s.\"%(vD)\n", "print \" The angular velocity of the link BD omegaBD = %.2f rad/s clockwise sbout B.\"%(omegaBD)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ " The velocity of the slider D vD = 1.6 m/s.\n", " The angular velocity of the link BD omegaBD = 36.96 rad/s clockwise sbout B.\n" ] } ], "prompt_number": 3 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 7.4 Page No : 151" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math \n", "\n", "# Variables:\n", "NBA = 120. \t\t\t#rpm\n", "AB = 150./1000 #mm\n", "DC = 450./1000 #mm\n", "BC = 450./1000 #mm\n", "dC = 50./1000\n", "rC = dC/2 \t\t\t#m\n", "\n", "#Solution:\n", "#Refer Fig. 7.12\n", "#Calculating the angular velocity of the crank AB\n", "omegaBA = 2*math.pi*NBA/60 \t\t\t#rad/s\n", "#Calculating the linear velocity of B with respect to A\n", "vBA = omegaBA*AB \t\t\t#m/s\n", "vB = vBA\n", "#By measurement from the velocity diagram Fig. 7.12(b)\n", "vF = 0.7\n", "vCD = 2.25\n", "vCB = 2.25 \t\t\t#m/s\n", "#Calculating the angular velocity of DC\n", "omegaDC = vCD/DC \t\t\t#rad/s\n", "#Calculating the angular velocity of BC\n", "omegaCB = vCB/BC \t\t\t#rad/s\n", "#Calculating the rubbing speed at the pin C\n", "vr = (omegaCB-omegaDC)*rC \t\t\t#The rubbing speed at the pin C m/s\n", "\n", "#Results:\n", "print \" The velocity of block F vF = %.1f m/s.\"%(vF)\n", "print \" The angular velocity of DC omegaDC = %d rad/s anticlockwise about D.\"%(omegaDC)\n", "print \" The rubbing speed at the pin C is %d m/s.\"%(vr)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ " The velocity of block F vF = 0.7 m/s.\n", " The angular velocity of DC omegaDC = 5 rad/s anticlockwise about D.\n", " The rubbing speed at the pin C is 0 m/s.\n" ] } ], "prompt_number": 4 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 7.5 Page No : 153" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math \n", "\n", "# Variables:\n", "NAO = 120. \t\t\t#rpm\n", "OA = 100./1000\n", "CE = 350./1000 \t\t\t#m\n", "\n", "#Solution:\n", "#Refer Fig. 7.13\n", "#Calculating the angular speed of the crank OA\n", "omegaAO = 2*math.pi*NAO/60 \t\t\t#rad/s\n", "#Calculating the velocity of A with respect to O\n", "vAO = omegaAO*OA \t\t\t#m/s\n", "vA = vAO\n", "#By measurement from the velocity diagram Fig. 7.14(b)\n", "vF = 0.53\n", "od = 1.08\n", "vCE = 0.44 \t\t\t#m/s\n", "#Calculating the angular velocity of CE\n", "omegaCE = vCE/CE \t\t\t#rad/s\n", "\n", "#Results:\n", "print \" The velocity of F vF = %.2f m/s.\"%(vF)\n", "print \" The velocity of sliding of CE in the trunnion is %.2f m/s.\"%(od)\n", "print \" The angular velocity of CE omegaCE = %.2f rad/s clockwise about E.\"%(omegaCE)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ " The velocity of F vF = 0.53 m/s.\n", " The velocity of sliding of CE in the trunnion is 1.08 m/s.\n", " The angular velocity of CE omegaCE = 1.26 rad/s clockwise about E.\n" ] } ], "prompt_number": 5 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 7.6 Page No : 155" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math \n", "\n", "# Variables:\n", "NCO = 120. \t\t\t#rpm\n", "OC = 125./1000 \t\t\t#m\n", "\n", "#Solution:\n", "#Refer Fig. 7.15\n", "#Calculating the angular velocity of the crank CO\n", "omegaCO = 2*math.pi*NCO/60 \t\t\t#rad/s\n", "#Calculating the linear velocity of C with respect to O\n", "vCO = omegaCO*OC \t\t\t#m/s\n", "vC = vCO\n", "#By measurement from the velocity diagram Fig. 7.16(b)\n", "\n", "vCO = 1.57\n", "vE = 0.7 \t\t\t#m/s\n", "\n", "#Results:\n", "print \" The absolute velocity of point E of the lever vE = %.1f m/s.\"%(vE)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ " The absolute velocity of point E of the lever vE = 0.7 m/s.\n" ] } ], "prompt_number": 7 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 7.7 Page No : 156" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math \n", "\n", "# Variables:\n", "NBO1 = 40. \t\t\t#rpm\n", "O1O2 = 800./1000\n", "O1B = 300./1000\n", "O2D = 1300./1000\n", "DR = 400./1000 \t\t\t#m\n", "\n", "#Solution:\n", "#Refer Fig. 7.18\n", "#Calculating the angular speed of the crank BO\n", "omegaBO1 = 2*math.pi*NBO1/60 \t\t\t#rad/s\n", "#Calculating the velocity of B with respect to O1\n", "vBO1 = omegaBO1*O1B \t\t\t#m/s\n", "vB = vBO1\n", "#By measurement from the velocity diagram Fig. 7.18(b)\n", "vR = 1.44\n", "vDO2 = 1.32 \t\t\t#m/s\n", "vD = vDO2\n", "#Calculating the angular velocity of the link O2D\n", "omegaDO2 = vDO2/O2D \t\t\t#rad/s\n", "\n", "#Results:\n", "print \" The velocity of the ram R vR = %.2f m/s.\"%(vR)\n", "print \" The angular velocity of the link O2D omegaDO2 = %.3f rad/s anticlockwise about O2.\"%(omegaDO2)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ " The velocity of the ram R vR = 1.44 m/s.\n", " The angular velocity of the link O2D omegaDO2 = 1.015 rad/s anticlockwise about O2.\n" ] } ], "prompt_number": 8 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 7.8 Page No : 158" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math \n", "\n", "# Variables:\n", "NAO1 = 60. \t\t\t#rpm\n", "O1A = 85.\n", "rQ = 50. \t\t\t#mm\n", "\n", "#Solution:\n", "#Refer Fig. 7.20 and Fig. 7.21\n", "#Calculating the angular velocity of AO1\n", "omegaAO1 = 2*math.pi*NAO1/60 \t\t\t#rad/s\n", "#Calculating the velocity of A with respect to O1\n", "vAO1 = omegaAO1*O1A \t\t\t#mm/s\n", "vA = vAO1\n", "#By measurement from the velocity diagram Fig. 7.20(b)\n", "vDO2 = 410. \t\t\t#mm/s\n", "O2D = 264. \t\t\t#mm\n", "angleB1O2B2 = 60*math.pi/180 \t\t\t#rad\n", "#To vary the Scilab function 'beta'\n", "alpha = 120\n", "beta = 240 \t\t\t#degrees\n", "#Calculating the angular velocity of the quadant Q\n", "omegaQ = vDO2/O2D \t\t\t#rad/s\n", "#Calculating the linear speed of the rack\n", "vR = omegaQ*rQ \t\t\t#mm/s\n", "#Calculating the ratio of times of lowering and raimath.sing the rack\n", "r = beta/alpha\n", "#Calculating the length of stroke of the rack\n", "L = rQ*angleB1O2B2 \t\t\t#mm\n", "\n", "#Results:\n", "print \" The linear speed of the rack vR = %.1f mm/s.\"%(vR)\n", "print \" The ratio of times of lowering and raising the rack is %d.\"%(r)\n", "print \" The length of the stroke of the rack is %.2f mm.\"%(L)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ " The linear speed of the rack vR = 77.7 mm/s.\n", " The ratio of times of lowering and raising the rack is 2.\n", " The length of the stroke of the rack is 52.36 mm.\n" ] } ], "prompt_number": 9 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 7.9 Page No : 160" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math \n", "\n", "# Variables:\n", "NPO = 120. \t\t\t#rpm\n", "OQ = 100./1000 #mm\n", "OP = 200./1000 #mm\n", "RQ = 150./1000 #mm\n", "RS = 500./1000 \t\t#m\n", "\n", "#Solution:\n", "#Refer Fig. 7.22\n", "#Calculating the angular speed of the crank PO\n", "omegaPO = 2*math.pi*NPO/60 \t\t\t#rad/s\n", "#Calculating the velocity of P with respect to O\n", "vPO = omegaPO*OP \t\t\t#m/s\n", "vP = vPO\n", "#By measurement from the velocity diagram Fig. 7.23(b)\n", "vS = 0.8\n", "vSR = 0.96\n", "vTP = 0.85 \t\t\t#m/s\n", "#Calculating the angular velocity of link RS\n", "omegaRS = vSR/RS \t\t\t#rad/s\n", "\n", "#Results:\n", "print \" The velocity of the slider S cutting tool vS = %.1f m/s.\"%(vS)\n", "print \" The angular velocity of the link RS omegaRS = %.2f rad/s clockwise about R.\"%(omegaRS)\n", "print \" The velocity of the sliding block T on the slotted lever QT vTP = %.2f m/s.\"%(vTP)\n", "\n", "# note : answer in book is wrong\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ " The velocity of the slider S cutting tool vS = 0.8 m/s.\n", " The angular velocity of the link RS omegaRS = 1.92 rad/s clockwise about R.\n", " The velocity of the sliding block T on the slotted lever QT vTP = 0.85 m/s.\n" ] } ], "prompt_number": 2 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 7.10 Page No : 162" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math \n", "\n", "# Variables:\n", "NAD = 100. \t\t\t#rpm\n", "TA = 50. \t\t\t#N-m\n", "DA = 300./1000\n", "CB = 360./1000\n", "AB = CB\n", "DC = 600./1000 \t\t\t#m\n", "eta = 70./100 \t\t\t#%\n", "\n", "#Solution:\n", "#Refer Fig. 7.25\n", "#Calculating the angular velocity of the crank AD\n", "omegaAD = 2*math.pi*NAD/60 \t\t\t#rad/s\n", "#Calculating the velocity of A with respect to D\n", "vAD = omegaAD*DA \t\t\t#m/s\n", "vA = vAD\n", "#By measurement from the velocity diagram Fig. 7.25(b)\n", "vBC = 2.25 \t\t\t#m/s\n", "vB = vBC\n", "#Calculating the angular velocity of the driven link CB\n", "omegaBC = vBC/CB \t\t\t#rad/s\n", "#Calculating the actual mechanical advantage\n", "omegaA = omegaAD\n", "omegaB = omegaBC\n", "MAactual = eta*omegaA/omegaB\n", "#Calculating the resisting torque\n", "TB = eta*TA*omegaA/omegaB \t\t\t#N-m\n", "\n", "#Results:\n", "print \" The velocity of the point B. vB = %.2f m/s.\"%(vB)\n", "print \" The angular velocity of the driven link CB. omegaBC = %.2f rad/s.\"%(omegaBC)\n", "print \" The actual mechanical advantage. M.A.actual) = %.2f.\"%(MAactual)\n", "print \" The resisting torque. TB = %.1f N-m.\"%(TB)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ " The velocity of the point B. vB = 2.25 m/s.\n", " The angular velocity of the driven link CB. omegaBC = 6.25 rad/s.\n", " The actual mechanical advantage. M.A.actual) = 1.17.\n", " The resisting torque. TB = 58.6 N-m.\n" ] } ], "prompt_number": 11 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 7.11 Page No : 163" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math \n", "\n", "# Variables:\n", "WC = 2.5*1000\n", "WD = 4.*1000 \t\t\t#N\n", "OA = 175./1000 #mm\n", "AB = 180./1000 #mm\n", "AD = 500./1000 #mm\n", "BC = 325./1000 \t\t\t#m\n", "\n", "#Solution:\n", "#Refer Fig. 7.26\n", "#Assuming the speed of crank OA to be 'N'\n", "#Calculating the angular velocity of crank OA\n", "#Assume the vector oa (i.e. velocity of A) as 20 m/s\n", "N = 20/(2*math.pi/60*OA) \t\t\t#mm\n", "#By measurement from the velocity diagram Fig. 7.27(b)\n", "vC = 35.\n", "vD = 21. \t\t\t#mm\n", "#Calculating the velocity ratio between C and the ram D\n", "r = vC/vD \t\t\t#The velocity ratio between C and the ram D\n", "#Calculating the efficiency of the machine\n", "eta = (WD*vD)/(WC*vC)*100 \t\t\t#%\n", "\n", "#Results:\n", "print \" The velocity ratio between C and the ram D is %.2f.\"%(r)\n", "print \" The efficiency of the machine eta = n %d %%.\"%(eta)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ " The velocity ratio between C and the ram D is 1.67.\n", " The efficiency of the machine eta = n 96 %.\n" ] } ], "prompt_number": 12 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 7.12 Page No : 165" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math \n", "\n", "# Variables:\n", "NAO = 180. \t\t\t#rpm\n", "OA = 180./1000 #mm\n", "CB = 240./1000 #mm\n", "AB = 360./1000 #mm\n", "BD = 540./1000 \t\t#mm\n", "FD = 2.*1000 \t\t\t#N\n", "DA = 30./1000\n", "DD = DA\n", "rA = DA/2\n", "rD = DD/2 \t\t\t#m\n", "\n", "#Solution:\n", "#Refer Fig. 7.28\n", "#Calculating the angular velocity of the crank OA\n", "omegaAO = 2*math.pi*NAO/60 \t\t\t#rad/s\n", "#Calculating the velocity of A with respect to O\n", "vAO = omegaAO*OA\n", "vA = vAO\n", "#By measurement fro the velocity diagram Fig. 7.29(b)\n", "vD = 2.05\n", "vBA = 0.9\n", "vBC = 2.8\n", "vDB = 2.4 \t\t\t#m/s\n", "#Calculating the angular velocity of the link AB\n", "omegaAB = vBA/AB \t\t\t#rad/s\n", "#Calculating the angular velocity of the link CB\n", "omegaCB = vBC/CB \t\t\t#rad/s\n", "#Calculating the angular velocity of the link BD\n", "omegaBD = vDB/BD \t\t\t#rad/s\n", "#Calculating the relative angular velocity at A\n", "rvA = omegaCB-omegaAB+omegaBD \t\t\t#The relative angular velocity at A rad/s\n", "#Calculating the relative angular velocity at D\n", "rvD = omegaBD \t\t\t#The relative angular velocity at D rad/s\n", "#Calculating the velocity of rubbing on the pin A\n", "vrA = rvA*rA*1000 \t\t\t#The velocity of rubbing on the pin A mm/s\n", "#Calculating the velocity of rubbing on the pin D\n", "vrD = rvD*rD*1000 \t\t\t#The velocity of rubbing on the pin D mm/s\n", "#Calculating the torque applied to crank OA\n", "TA = FD*vD/omegaAO \t\t\t#N-m\n", "\n", "#Results:\n", "print \" The velocity of slider D vD = %.2f m/s.\"%(vD)\n", "print \" The angular velocity of the link AB, omegaAB = %.1f rad/s, anticlockwise about A.\"%(omegaAB)\n", "print \" The angular velocity of the link CB, omegaCB = %.2f rad/s, anticlockwise about C.\"%(omegaCB)\n", "print \" The angular velocity of the link BD, omegaBD = %.2f rad/s, clockwise about B.\"%(omegaBD)\n", "print \" The velocity of rubbing on the pin A is %d mm/s.\"%(vrA)\n", "print \" The velocity of rubbing on the pin D is %d mm/s.\"%(vrD)\n", "print \" The torque applied to the crank OA, TA = %.1f N-m.\"%(TA)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ " The velocity of slider D vD = 2.05 m/s.\n", " The angular velocity of the link AB, omegaAB = 2.5 rad/s, anticlockwise about A.\n", " The angular velocity of the link CB, omegaCB = 11.67 rad/s, anticlockwise about C.\n", " The angular velocity of the link BD, omegaBD = 4.44 rad/s, clockwise about B.\n", " The velocity of rubbing on the pin A is 204 mm/s.\n", " The velocity of rubbing on the pin D is 66 mm/s.\n", " The torque applied to the crank OA, TA = 217.5 N-m.\n" ] } ], "prompt_number": 15 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 7.13 Page No : 167" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math \n", "\n", "# Variables:\n", "NBA = 180 \t\t\t#rpm\n", "AB = 0.45 #m\n", "BD = 1.5 #m\n", "BC = 0.9 #m\n", "CE = BC \t\t\t#m\n", "FD = 500.\n", "FE = 750. \t\t\t#N\n", "\n", "#Solution:\n", "#Refer Fig. 7.31\n", "#Calculating the angular velocity of the crank AB\n", "omegaBA = 2*math.pi*NBA/60 \t\t\t#rad/s\n", "#Calculating the velocity of B with respect to A\n", "vBA = omegaBA*AB \t\t\t#m/s\n", "vB = vBA\n", "#By measurement from the velocity diagram Fig. 7.31(b)\n", "vD = 9.5\n", "vE = 1.7 \t\t\t#m/s\n", "#Calculating the power input\n", "Pi = FD*vD-FE*vE \t\t\t#N-m/s\n", "#Calculating the turning moment at A\n", "TA = Pi/omegaBA \t\t\t#N-m\n", "\n", "#Results:\n", "print \" The velocity of slider D, vD = %.1f m/s.\"%(vD)\n", "print \" The velocity of slider E, vE = %.1f m/s.\"%(vE)\n", "print \" The turning moment at A, TA = %.1f N-m.\"%(TA)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ " The velocity of slider D, vD = 9.5 m/s.\n", " The velocity of slider E, vE = 1.7 m/s.\n", " The turning moment at A, TA = 184.4 N-m.\n" ] } ], "prompt_number": 16 } ], "metadata": {} } ] }