{ "cells": [ { "cell_type": "markdown", "metadata": {}, "source": [ "# Chapter 11: Rotation" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 11.10: Sample_Problem_10.sce" ] }, { "cell_type": "code", "execution_count": null, "metadata": { "collapsed": true }, "outputs": [], "source": [ "//Given that\n", "m = 1 //(say)\n", "R = 0.15 //in meter\n", "L = 2.0 * R\n", "g = 9.8 //in m/s^2\n", "\n", "//Sample Problem 11-10\n", "printf('**Sample Problem 11-10**\n')\n", "I = 0.5*m*R^2 + m*L^2/12 + m*(L/2+R)^2\n", "deltaU = m* g* (L + 2*R)\n", "//deltaK = 0.5*I*w^2\n", "//therefore-\n", "w = sqrt(deltaU/(0.5*I))\n", "printf('The angular speed is equal to %frad/s', w)" ] } , { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 11.1: Sample_Problem_1.sce" ] }, { "cell_type": "code", "execution_count": null, "metadata": { "collapsed": true }, "outputs": [], "source": [ "//Given that\n", "t = poly(0, 't')\n", "A = -1.00-0.600*t+0.250*t^2\n", "\n", "//Sample Problem 11-1a\n", "printf('**Sample Problem 11-1a**\n')\n", "Ts = [-3:0.5:6]\n", "As = horner(A, Ts)\n", "xset('window', 1)\n", "xtitle( 'angular variable for the disk v/s time', 'time(sec)', 'Y-axis')\n", "plot(Ts, As, 'm-o')\n", "\n", "//Sample Problem 11-1b\n", "printf('\n**Sample Problem 11-1b**\n')\n", "To = roots(derivat(A))\n", "printf('At t=%fsec, theta approaches its minimum value equal to %f\n', To, horner(A, To))\n", "\n", "//Sample Problem 11-1c\n", "printf('\n**Sample Problem 11-1c**\n')\n", "Os = horner(derivat(A), Ts)\n", "plot(Ts, Os, 'r-+')\n", "legend('theta(rad)', 'omega(rad/s)')" ] } , { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 11.2: Sample_Problem_2.sce" ] }, { "cell_type": "code", "execution_count": null, "metadata": { "collapsed": true }, "outputs": [], "source": [ "//Given that\n", "alpha = 0.335 //in rad/s^2\n", "Wo = -4.6 //in rad/s\n", "Ao = 0 //in rad\n", "Af = 5* 2*%pi //in rad\n", "\n", "//Sample Problem 11-2a\n", "printf('**Sample Problem 11-2a**\n')\n", "//Using newton's second equation of motion\n", "t = poly(0, 't')\n", "p = Ao + Wo*t + 0.5*alpha*t^2 - Af\n", "to = roots(p)\n", "printf('At time equal to %fsec, the reference line will be at given position\n', to(2))\n", "\n", "//Sample Problem 11-2c\n", "printf('\n**Sample Problem 11-2c**\n')\n", "p = Wo + alpha*t\n", "ts = roots(p)\n", "printf('At time equal to %fsec, the disk momentarily stops', ts)" ] } , { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 11.3: Sample_Problem_3.sce" ] }, { "cell_type": "code", "execution_count": null, "metadata": { "collapsed": true }, "outputs": [], "source": [ "//Given that\n", "W1 = 3.40 //in rad/s\n", "W2 = 2.00 //in rad/s\n", "rev_taken = 20\n", "\n", "//Sample Problem 11-3a\n", "printf('**Sample Problem 11-3a**\n')\n", "angle_traversed = 2*%pi*rev_taken\n", "//Using newton's third equation of motion\n", "//Wf^2 = Wi^2 + 2*alpha*theta\n", "alpha = (W2^2 - W1^2)/(2*angle_traversed)\n", "printf('The angular acceleration during the stop is %frads^2\n', alpha)\n", "\n", "//Sample Problem 11-3b\n", "printf('\n**Sample Problem 11-3b**\n')\n", "//Using newton's first equation of motion\n", "time_taken = (W2 - W1)/alpha\n", "printf('The time taken in decreasing the speed is %fsec', time_taken)" ] } , { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 11.4: Sample_Problem_4.sce" ] }, { "cell_type": "code", "execution_count": null, "metadata": { "collapsed": true }, "outputs": [], "source": [ "//Given that\n", "r = 15 //in meter\n", "g = 9.8 //in m.s^2\n", "a = 11 * g //in m.s^2\n", "\n", "//Sample Problem 11-4a\n", "printf('**Sample Problem 11-4a**\n')\n", "w = sqrt(a/r)\n", "printf('The angular speed should be %frad/s\n', w)\n", "\n", "//Sample Problem 11-4b\n", "printf('\n**Sample Problem 11-4b**\n')\n", "t = 120 //in sec\n", "alpha = w/t\n", "at = alpha*r\n", "printf('The tangential acceleration will be %fm/s^2', at)" ] } , { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 11.6: Sample_Problem_6.sce" ] }, { "cell_type": "code", "execution_count": null, "metadata": { "collapsed": true }, "outputs": [], "source": [ "//Given that\n", "M = 272 //in kg\n", "R = 38*10^-2 //in meter\n", "w = 14000* 2*%pi/60 //in rad/s\n", "\n", "///Sample Problem 11-6\n", "printf('**Sample Problem 11-6**\n')\n", "I = 0.5* M* R^2\n", "E = 0.5* I* w^2\n", "printf('The energy released during the explosion is %eJ', E)" ] } , { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 11.7: Sample_Problem_7.sce" ] }, { "cell_type": "code", "execution_count": null, "metadata": { "collapsed": true }, "outputs": [], "source": [ "//Given that\n", "M = 2.5 //in kg\n", "R = 0.20 //i meter\n", "m = 1.2 //in kg\n", "g = 9.8 //in m/s^2\n", "I = 0.5*M*R^2\n", "\n", "//Sample Problem 11-7\n", "printf('**Sample Problem 11-7**\n')\n", "//mg - T = ma\n", "//T*R = I*a/R\n", "//T = I*a/R^2\n", "//on adding =>\n", "a = m*g/(m+I/R^2)\n", "T = m*(g-a)\n", "alpha = a/R\n", "printf('The acceleration of the block is %fm/s^2\n', a)\n", "printf('The angular acceleration of the pulley is %frad/s^2\n', alpha)\n", "printf('The tension in the string is %fN', T)" ] } , { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 11.8: Sample_Problem_8.sce" ] }, { "cell_type": "code", "execution_count": null, "metadata": { "collapsed": true }, "outputs": [], "source": [ "//Given that\n", "M = 80 //in kg\n", "d1 = 0.30 //in meter\n", "alpha = 6 //in rad/s^2\n", "I = 15 //in kg.m^2\n", "g = 9.8 //in m/s^2\n", "\n", "//Sample Problem 11-8a\n", "printf('**Sample Problem 11-8a**\n')\n", "F = I*alpha/d1\n", "printf('The magnitude of F is %fN\n', F)\n", "\n", "//Sample Problem 11-8b\n", "printf('\n**Sample Problem 11-8b**\n')\n", "d2 = 0.12 //in meter\n", "//F*d1 - M*g*d2 = I*alpha\n", "F = I*alpha + M*g*d2\n", "F = F/d1\n", "printf('The magnitude of F in second case is %fN', F)" ] } , { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 11.9: Sample_Problem_9.sce" ] }, { "cell_type": "code", "execution_count": null, "metadata": { "collapsed": true }, "outputs": [], "source": [ "exec('Example11_7.sce', -1)\n", "clc\n", "\n", "//Given that\n", "t = 2.5 //in sec\n", "\n", "//Sample Problem 11-9\n", "printf('\n**Sample Problem 11-9**\n')\n", "w = 0 + alpha*t\n", "RE = 0.5* I* w^2\n", "printf('The rotational kinetic energy of the disk will be %fJ', RE)" ] } ], "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 }