{ "cells": [ { "cell_type": "markdown", "metadata": {}, "source": [ "# Chapter 2: Motion Inertia" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 2.10: Find_acceleration.sce" ] }, { "cell_type": "code", "execution_count": null, "metadata": { "collapsed": true }, "outputs": [], "source": [ "\n", "clc\n", "//given\n", "Ia=200//lb ft2\n", "Ib=15//lb ft2\n", "G=5//wb==5*wa\n", "m=150//lb\n", "r=8//in\n", "printf('\n')\n", "//the equivalent mass of the geared system referred to the circumference of the drum is given by\n", "//Me=(1/r)^2*(Ia+(G^2*Ib))\n", "Me=(12/r)^2*(Ia+(G^2*Ib))\n", "M=m+Me\n", "a=(m/M)*32.2//acceleration\n", "//if efficiency of gearing is 90% then Me=(1/r^2)*(Ia+(G^2*Ib)/n)\n", "n=.9\n", "Me1=(12/r)^2*(Ia+(G^2*Ib)/n)\n", "M1=Me1+m\n", "a1=(m/M1)*32.2\n", "printf('acceleration = %.2f ft/s2\n',a)\n", "printf('acceleration when gear efficiency is 0.9= %.2f ft/s2\n',a1)" ] } , { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 2.11: Maximum_acceleratio.sce" ] }, { "cell_type": "code", "execution_count": null, "metadata": { "collapsed": true }, "outputs": [], "source": [ "\n", "clc\n", "printf('\n')\n", "//let\n", "//S=displacement of car from rest with uniform acceleration a, the engine torque T assumed to remain ocnstant\n", "//v=final speed ofcar\n", "//G=gear ratio\n", "//r=effective radius\n", "//n=efficiency of transmission\n", "//M=mass of the car\n", "//Ia and Ib=moments of inertia of road whels and engine \n", "//formulas => F=29.5nG ; Me= 1648+$.54nG^2 ; a=32.2 F/Me\n", "//given\n", "G1=22.5\n", "G2=12.5\n", "G3=7.3\n", "G4=5.4\n", "n=.82//for 1st ,2nd and 3rd gear\n", "n4=.9//for 4th gear\n", "F1=29.5*n*G1\n", "F2=29.5*n*G2\n", "F3=29.5*n*G3\n", "F4=29.5*n4*G4\n", "//on reduction and putting values we get\n", "Me1=1648+4.54*n*G1^2\n", "Me2=1648+4.54*n*G2^2\n", "Me3=1648+4.54*n*G3^2\n", "Me4=1648+4.54*n4*G4^2\n", "a1=32.2*F1/Me1\n", "a2=32.2*F2/Me2\n", "a3=32.2*F3/Me3\n", "a4=32.2*F4/Me4\n", "printf('Maximum acceleration of car on top gear is %.2f ft/s^2 \n',a4)\n", "printf('Maximum acceleration of car on third gear is %.2f ft/s^2 \n',a3)\n", "printf('Maximum acceleration of car on second gear is %.2f ft/s^2 \n',a2)\n", "printf('Maximum acceleration of car on first gear is %.2f ft/s^2 \n',a1)" ] } , { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 2.12: couple_supplied.sce" ] }, { "cell_type": "code", "execution_count": null, "metadata": { "collapsed": true }, "outputs": [], "source": [ "\n", "clc\n", "printf('\n')\n", "//given\n", "I=40//lb ft2\n", "n=500//rpm\n", "w=%pi*n/30//angular velocity\n", "wp=2*%pi/5//angular velocity of precession\n", "I1=I/32.2\n", "T=I1*w*wp//gyroscopic couple\n", "printf('the couple supplied to the shaft= %.2f lb ft\n',T)" ] } , { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 2.13: g_y_r_o_s_c_o_p_i_c_r_e_a_c_t_i_o.sce" ] }, { "cell_type": "code", "execution_count": null, "metadata": { "collapsed": true }, "outputs": [], "source": [ "\n", "clc\n", "//given\n", "printf('\n')\n", "I=250//lb ft2\n", "n=1600//rpm\n", "v=150//mph\n", "r=500//ft\n", "w=%pi*160/3//angular velocity of rotation\n", "wp=(150*88)/(60*500)//angular velocity of precession\n", "//a) with three bladed screw\n", "//T=I*w*wp\n", "T=(250/32.2)*%pi*(160/3)*wp\n", "//b)with two bladed air screw\n", "//T1=2*I*w*wp*sin(o)\n", "printf('The magnitude of gyroscopic couple is given by %.0f lb ft\n',T)\n", "//Tix=T(1-cos(2o)) lb ft\n", "//T1y=Tsin(2o)) lb ft\n", "printf('The component gyroscopic couple in the vertical plane =%.0f(1-cos(2x)) lb ft\n',T)\n", "printf('The component gyroscopic couple in the horizontal plane =%.0f(sin(2x)) lb ft\n',T)" ] } , { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 2.1: find_velocity_and_kinetic_energy.sce" ] }, { "cell_type": "code", "execution_count": null, "metadata": { "collapsed": true }, "outputs": [], "source": [ "\n", "clc\n", "//a) INELASTIC\n", "//for sphere 1 ,mass=m1 and initial velocity=u1 \n", "//for sphere 2 ,mass=m2 and initial velocity=u2\n", "m1=100//lb\n", "u1=10//ft/s\n", "m2=50//lb\n", "u2=5//ft/s\n", "v=(m1*u1+m2*u2)/(m1+m2)\n", "//change in kinetic energy\n", "//initial kinetic energy = ke1\n", "ke1=(m1*(u1^2)+m2*(u2^2))/(2*32.2)\n", "//Kinetic Energy after inelastic colision = ke2\n", "ke2=((m1+m2)*8.333^2)/(2*32.2)\n", "//Change in Kinetic Energy =l\n", "l=ke1-ke2\n", "//b) Elastic\n", "// for a very short time bodies will have a common velocity given by v=8.333 ft/s\n", "// for a very short time bodies will have a common velocity given by v=8.333 ft/s\n", "//immidiately after impact ends the velocities for both the bodies are given by v1 and v2\n", "v1=2*v-u1\n", "v2=2*v-u2\n", "//c) Coeeficient of Restitution=0.6\n", "e=0.6\n", "ve1=(1+e)*v-e*u1\n", "ve2=(1+e)*v-e*u2\n", "ke3=(m1*(ve1^2)+m2*(ve2^2))/(2*32.2)\n", "loss=ke1-ke3\n", "printf('kinetic energy before collisio0n is %f ft lb\n',ke1)\n", "printf('\n')\n", "printf('a) INELASTIC\n')\n", "printf('\n')\n", "printf('velocity after collision is %f ft/s\n',v)\n", "printf('the Kinetic Energy after collision is %f ft lb\n',ke2) \n", "printf('the change in Kinetic Energy after collision is %f ft lb\n',l)\n", "printf('\n')\n", "printf('b) ELASTIC\n')\n", "printf('\n')\n", "printf('velocity of 1 after collision is %f ft/s\n',v1)\n", "printf('velocity of 2 after collision is %f ft/s\n',v2)\n", "printf('there is no loss of kinetic energy in case of elastic collision\n')\n", "printf('\n')\n", "printf('c) e=0.6\n')\n", "printf('\n')\n", "printf('velocity of 1 after collision is %f ft/s\n',ve1)\n", "printf('velocity of 2 after collision is %f ft/s\n',ve2)\n", "printf('the Kinetic Energy after collision is %f ft lb\n',ke3) \n", "printf('the change in Kinetic Energy after collision is %f ft lb\n',loss)" ] } , { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 2.2: speed_of_truck.sce" ] }, { "cell_type": "code", "execution_count": null, "metadata": { "collapsed": true }, "outputs": [], "source": [ "\n", "clc\n", "//given\n", "m1=15//tons\n", "u1=12//m/h\n", "m2=5//tons\n", "u2=8//m/h\n", "k=2//ton/in\n", "e1=0.5//coefficient of restitution\n", "printf('\n')\n", "//conservation of linear momentum\n", "v=(m1*u1+m2*u2)/(m1+m2)\n", "printf('velocity at the instant of collision is %.2f mph',v)\n", "e=(m1*m2*(88/60)^2*(u1-u2)^2)/(2*32.2*(u1+u2))\n", "printf('\n')\n", "printf('The difference between the kinetic energy before and during the impact is %.2f ft tons\n',e)\n", "//energy stored in spring equals energy dissipated\n", "//s=(1/2)*k*x^2\n", "//s=e\n", "//since there are 4 buffer springs ,4x^2=24 inches (2 ft=24 inches)\n", "x=((e*12)/4)^.5\n", "printf('Maximum deflection of the spring is %.2f in\n',x)\n", "// maximum force acting between pair of buffer = stiffness of spring*deflection\n", "f=k*x\n", "printf('Maximum force acting between each buffer is %.2f tons\n',f)\n", "//assuming perfectly elastic collision\n", "//for loaded truck \n", "v1=2*11-12\n", "//for unloaded truck \n", "v2=2*11-8\n", "printf('Speed of loaded truck after impact %.2f mph\n',v1)\n", "printf('speed of unloaded truck after impact %.2f mph\n',v2)\n", "//if coefficient of restitution =o.5\n", "//for loaded truck \n", "ve1=(1+.5)*11-.5*12\n", "//for unloaded truck \n", "ve2=(1+.5)*11-.5*8\n", "printf('Speed of loaded truck after impact when e=0.5 %.2f mph\n',ve1)\n", "printf('Speed of unloaded truck after impact when e=0.5 %.2f mph\n',ve2)\n", "//net loss of kinetic energy=(1-e^2)*energy stored in spring\n", "l=(1-(e1^2))*2//ft tons\n", "printf('Net loss of kinetic energy is %.2f ft tons\n',l)" ] } , { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 2.3: Maximum_twist.sce" ] }, { "cell_type": "code", "execution_count": null, "metadata": { "collapsed": true }, "outputs": [], "source": [ "\n", "clc\n", "//given\n", "m1=500//lb ft^2\n", "m2=1500//lb ft^2\n", "k=150//lb ft^2\n", "w1=150//rpm\n", "\n", "N=(w1*m1)/(m1+m2)\n", "printf('Angular velocity at the instant when speeds of the flywheels are equalised is given by %.2f r.p.m\n',N)\n", "//kinetic energy at this instance \n", "ke1=(1/2)*((m1+m2)/32.2)*((%pi*N)/30)^2\n", "printf('The kinetic energy of the system at this instance is %.2f ft lb\n',ke1)\n", "printf('which is almost equal to 480 ft lb \n')\n", "//initial kinetic energy\n", "ke0=(1/2)*((m1)/32.2)*((%pi*w1)/30)^2\n", "printf('The initial kinetic energy of the system is %.2f ft lb\n',ke0)\n", "printf('which is almost equal to 1915 ft lb \n')\n", "//strain energy = s\n", "s=ke0-ke1\n", "printf('strain energy stored in the spring is %.2f ft lb which is approximately 1435 ft lb\n',s)\n", "\n", "x=((1435*2)/150)^.5\n", "printf('Maximum angular displacement is %.2f in radians which is equal to 250 degrees\n',x)\n", "//na1 and na are initial and final speeds of the flywheel 1 and same nb1 and nb for flywheel 2 \n", "na=2*N-w1//w1=na1\n", "nb=2*N-0//nb1=0\n", "printf ('Speed of flywheel a and b when spring regains its unstrained position are %.2f rpm and %.2f rpm respectively\n',na,nb)" ] } , { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 2.4: Length_of_equivalebt_pendulum.sce" ] }, { "cell_type": "code", "execution_count": null, "metadata": { "collapsed": true }, "outputs": [], "source": [ "\n", "clc\n", "//given\n", "m1=150 //lb\n", "l=3//ft\n", "//number of oscillation per second is given by n\n", "printf('\n')\n", "n=(50/92.5)\n", "printf ('number of oscillation per second = %.2f\n',n)\n", "//length of simple pendulum is given by L=g/(2*%pi*n)^2\n", "L=32.2/(2*%pi*n)^2\n", "printf ('length of simple pendulum = %.2f ft\n',L)\n", "// distance of cg from point of suspension is given by a\n", "a=25/12\n", "k=(a*(L-a))^.5//radius of gyration\n", "moi=m1*k^2\n", "printf('The moment of inertia of rod is %.2f lb ft^2',moi)" ] } , { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 2.5: Moment_of_inertia.sce" ] }, { "cell_type": "code", "execution_count": null, "metadata": { "collapsed": true }, "outputs": [], "source": [ "clc;\n", "n1=50/84.4\n", "n2=50/80.3\n", "\n", "L1=(32.2*12)*(84.4/(100*%pi))^2\n", "L2=(32.2*12)*(80.3/(100*%pi))^2\n", "//a1(L1-a1)=k^2=a2(L2-a2) and a1+a2=30 inches\n", "//substituting and solving for a we get \n", "a1=141/6.8\n", "a2=30-a1\n", "k=(a1*(L1-a1))^.5\n", "moi=90*(149/144)//moi=m*k^2\n", "printf('length of equivalent simple pendulum when axis coincides with small end and big end respectively-\n')\n", "printf('L1=%.1f in\n',L1)\n", "printf('L2=%.1f in\n',L2)\n", "printf('distances of cg from small end and big end centers respectively are-\n')\n", "printf('a1=%.1f in\n',a1)\n", "printf('a2=%.1f in\n',a2)\n", "printf('Moment of inertia of rod =%.2f lb ft^2',moi)" ] } , { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 2.6: radius_of_gyratio.sce" ] }, { "cell_type": "code", "execution_count": null, "metadata": { "collapsed": true }, "outputs": [], "source": [ "\n", "clc\n", "//given\n", "printf('\n')\n", "m1=150\n", "l=8.5\n", "g=32.2\n", "a=83.2\n", "n=25\n", "//k=(a/2*%pi*n)*(g/l)^0.5\n", "k=(14*a*((g)^0.5))/(2*%pi*n*(l^0.5))\n", "k1=14.5/12\n", "printf('radius of gyration is %.2f inches which is equal to %.2f ft \n',k,k1)\n", "moi=m1*(k1^2)\n", "printf('moment of inertia=%.2f lb ft^2',moi)" ] } , { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 2.7: Dynamical_system.sce" ] }, { "cell_type": "code", "execution_count": null, "metadata": { "collapsed": true }, "outputs": [], "source": [ "clc\n", "printf('\n')\n", "//given\n", "m=2.5//lb\n", "a=6//in\n", "k=3.8//in\n", "l=9//in\n", "c=3//in\n", "w=22500\n", "//k^2=ab\n", "//case a) to find equivalent dynamic system\n", "b=(k^2)/a\n", "ma=(2.5*6)/8.42//m*a/a+b\n", "mb=m-ma\n", "printf('Mass ma =%.2f lb will be situated at 6 inches from cg \n and mb =%.2f lb will be situated at %.2f inches \n from cg in the equivalent dynamical system',ma,mb,b)\n", "printf('\n')\n", "//if two masses are situated at the bearing centres \n", "ma1=(2.5*6)/9\n", "mb1=m-ma1\n", "k1=(a*c)^.5\n", "//t=m*((k1^2)-(k^2))*w\n", "t=((2.5*(18-3.8^2))*22500)/(32.2*12*12)\n", "printf('correction couple which must be applied in order that the two mass system is dynamically equivalent to the rod is given by %.2f lb ft\n',t)\n", "" ] } , { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 2.8: Find_forces.sce" ] }, { "cell_type": "code", "execution_count": null, "metadata": { "collapsed": true }, "outputs": [], "source": [ "\n", "clc\n", "printf('\n')\n", "m=20//lb\n", "g=32.2\n", "a=200//ft/s^2\n", "w=120//rad/s^2\n", "k=7//in\n", "f=(m/g)*a//effective force appllied to the link\n", "//this force acts parallel to the acceleration fg\n", "t=(m/g)*(k/12)^2*w//couple required in order to provide the angular acceleration\n", "//the line of action of F is therefore at a distance from G given by\n", "x=t/f\n", "printf('Effective force applied to the link is %.3f lb and the line of action of F is therefore at a distance from G given by %.3f ft \n',f,x)\n", "printf('F is the resultant of Fa and Fb, using x as shown in figure.25 , the force F may then be resolved along the appropriate lines of action to give the magnitudes of Fa and Fb\n')\n", "printf('From the scaled diagram shown in figure we get,Fa=65 lb and Fb=91 lb\n')" ] } , { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 2.9: Find_force.sce" ] }, { "cell_type": "code", "execution_count": null, "metadata": { "collapsed": true }, "outputs": [], "source": [ "\n", "clc\n", "printf('\n')\n", "//given\n", "m=10//ton\n", "m2=1000//lb\n", "a=3//ft/s^2\n", "//the addition to actual mass in order to allow for the rotational inertia of the wheels and axles\n", "m1=2*(1000/2240)*(15/21)^2//m1=m2*k^2/r^2 and 1 ton=2240 lbs\n", "M=m+m1\n", "F=3*(10.46/32.2)//F=M.a\n", "f=F*2240//lb\n", "Fa=(2*1000/2240)*(3/32.2)*(15/21)^2//total tangential force required in order to provide the angular acceleration of the wheels and axles\n", "//Limiting friction force =uW \n", "//u*10>0.042\n", "u=0.042/10\n", "printf('The total tangential force required in order to provide the angular acceleration of the wheels and axles is %.4f ton\n',Fa)\n", "printf('If there is to be pure rolling ,u>%.4f',u)\n", "" ] } ], "metadata": { "kernelspec": { "display_name": "Scilab", "language": "scilab", "name": "scilab" }, "language_info": { "file_extension": ".sce", "help_links": [ { "text": "MetaKernel Magics", "url": "https://github.com/calysto/metakernel/blob/master/metakernel/magics/README.md" } ], "mimetype": "text/x-octave", "name": "scilab", "version": "0.7.1" } }, "nbformat": 4, "nbformat_minor": 0 }