{ "metadata": { "name": "", "signature": "" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "heading", "level": 1, "metadata": {}, "source": [ "Chapter 10, Waves in solids" ] }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 1, page 406" ] }, { "cell_type": "code", "collapsed": false, "input": [ "from __future__ import division\n", "# Young's modulus of steel\n", "#given data :\n", "p=7.8*10**3 # in kg/m**3\n", "v=5200 # m/s\n", "Y=p*v**2 \n", "print \"Young modulus of steel, Y = %0.1e N/m^2 \" %Y" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Young modulus of steel, Y = 2.1e+11 N/m^2 \n" ] } ], "prompt_number": 2 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 2, page 406" ] }, { "cell_type": "code", "collapsed": false, "input": [ "from math import sqrt\n", "# Velocity and wavelength\n", "#given data :\n", "Y=8*10**10 # in N/m**2\n", "p=5000 # in kg/m**3\n", "v=sqrt(Y/p) \n", "print \"(1) The velocity, v = %0.f m/s \" %v\n", "f=400 # in vibration/sec\n", "lamda=v/f \n", "print \"(2) The wavelength = %0.f m \" %lamda" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "(1) The velocity, v = 4000 m/s \n", "(2) The wavelength = 10 m \n" ] } ], "prompt_number": 4 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 3, page 406" ] }, { "cell_type": "code", "collapsed": false, "input": [ "# Velocity and wavelength\n", "#given data :\n", "Y=7*10**10 # in N/m**2\n", "p=2.8*10**3 # in kg/m**3\n", "v=sqrt(Y/p) \n", "print \"(1) The velocity, v = %0.e m/s \" %v\n", "f=500 # in vibration/sec\n", "lamda=v/f \n", "print \"(2) The wavelength = %0.f m \" %lamda" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "(1) The velocity, v = 5e+03 m/s \n", "(2) The wavelength = 10 m \n" ] } ], "prompt_number": 7 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 4, page 410" ] }, { "cell_type": "code", "collapsed": false, "input": [ "# Young's modulus\n", "#given data :\n", "l=3 # in m\n", "n=600 # in Hz\n", "p=8.3*10**3 # in kg/m**3\n", "Y=p*n**2*(2*l)**2 \n", "print \"Youngs modulus, Y = %0.3e N/m^2 \" %Y" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Youngs modulus, Y = 1.076e+11 N/m^2 \n" ] } ], "prompt_number": 9 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 5, page 411" ] }, { "cell_type": "code", "collapsed": false, "input": [ "# Frequency\n", "#given data :\n", "Y=2*10**11 # in N/m**2\n", "p=8*10**3 # in kg/m**3\n", "l=0.25 # in m\n", "n=sqrt(Y/p)/(2*l) \n", "print \"The frequency, n = %0.e vibrations/s \" %n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The frequency, n = 1e+04 vibrations/s \n" ] } ], "prompt_number": 11 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 6, page 411" ] }, { "cell_type": "code", "collapsed": false, "input": [ "# Area of cross section\n", "#given data :\n", "n1BYn2=20 \n", "T=20*9.8 # in N\n", "Y=19.6*10**10 # in N/m**2\n", "alfa=n1BYn2**2*T/Y \n", "print \"Area of cross section, alfa = %0.e m^2 \" %alfa" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Area of cross section, alfa = 4e-07 m^2 \n" ] } ], "prompt_number": 13 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 7, page 412" ] }, { "cell_type": "code", "collapsed": false, "input": [ "# Velocity and Young modulus\n", "#given data :\n", "n=2600 # in Hz\n", "l=1 # in m\n", "p=7.8*10**3 # kg/m**3\n", "v=2*n*l \n", "print \"The velocity, v = %0.f m/s \" % v\n", "Y=v**2*p \n", "print \"Youngs modulus, Y = %0.2e N/m^2 \" %Y" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The velocity, v = 5200 m/s \n", "Youngs modulus, Y = 2.11e+11 N/m^2 \n" ] } ], "prompt_number": 14 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 8, page 412" ] }, { "cell_type": "code", "collapsed": false, "input": [ "# Frequencies\n", "#given data :\n", "Y=7.1*10**10 # in N/m**2\n", "p=2700 #in kg/m**3\n", "l=1.5 # in m\n", "r1=1 \n", "r2=3 \n", "r3=5 \n", "n1=(r1/(4*l))*sqrt(Y/p) \n", "n2=(r2/(4*l))*sqrt(Y/p) \n", "n3=(r3/(4*l))*sqrt(Y/p) \n", "print \"Frequency of first harmonic, n1 = %0.2f Hz \" %n1\n", "print \"Frequency of second harmonic, n2 = %0.2f Hz \" %n2\n", "print \"Frequency of third harmonic, n3 = %0.2f Hz \" %n3" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Frequency of first harmonic, n1 = 854.67 Hz \n", "Frequency of second harmonic, n2 = 2564.00 Hz \n", "Frequency of third harmonic, n3 = 4273.33 Hz \n" ] } ], "prompt_number": 15 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 9, page 428" ] }, { "cell_type": "code", "collapsed": false, "input": [ "from math import pi\n", "# Frequency\n", "#given data :\n", "l=1.2 # in m\n", "v=5150 # in m/s\n", "d=0.006 # in m\n", "k=d/sqrt(12) \n", "v1=pi*v*k*3.011**2/(8*l**2) \n", "print \"The frequency, v1 = %0.2f Hz \" %v1" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The frequency, v1 = 22.05 Hz \n" ] } ], "prompt_number": 17 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 10, page 429" ] }, { "cell_type": "code", "collapsed": false, "input": [ "from math import pi\n", "# Frequencies\n", "#given data :\n", "l=2 # in m\n", "v=3560 # in m/s\n", "r=0.004 # in m\n", "k=r/2 \n", "v1=pi*v*k*3.011**2/(8*l**2) \n", "print \"The frequency, v1 = %0.2f Hz \" %v1\n", "v2=pi*v*k*5**2/(8*l**2) \n", "print \"The frequency of first overtone, v2 = %0.2f Hz\" %v2\n", "v3=pi*v*k*7**2/(8*l**2) \n", "print \"The frequency of second overtone, v3 = %0.2f Hz\" %v3" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The frequency, v1 = 6.34 Hz \n", "The frequency of first overtone, v2 = 17.48 Hz\n", "The frequency of second overtone, v3 = 34.25 Hz\n" ] } ], "prompt_number": 18 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 11, page 429" ] }, { "cell_type": "code", "collapsed": false, "input": [ "# Frequency\n", "#given data :\n", "Y=7.1*10**10 # in N/m**2\n", "p=2.7*10**3 # in kg/m**3\n", "r=0.005 # in m\n", "vu=sqrt(Y/p) \n", "k=r/2 \n", "v=vu/(2*pi*k) \n", "print \"The frequency, v = %0.2e Hz \" %v" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The frequency, v = 3.26e+05 Hz \n" ] } ], "prompt_number": 20 } ], "metadata": {} } ] }