{
 "metadata": {
  "name": "",
  "signature": ""
 },
 "nbformat": 3,
 "nbformat_minor": 0,
 "worksheets": [
  {
   "cells": [
    {
     "cell_type": "heading",
     "level": 1,
     "metadata": {},
     "source": [
      "Chapter 9, Longitudinal acoustic waves in air"
     ]
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Example 1, page 380"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "from __future__ import division\n",
      "from math import pi\n",
      "# Pressure amplitude, Energy density and Energy flux\n",
      "#given data :\n",
      "A=1*10**-5 # in m\n",
      "n=500 # in per sec\n",
      "v=340 # in m/s\n",
      "p=1.29 # in kg/m**3\n",
      "Pa=2*pi*n*v*p*A \n",
      "print \"Pressure amplitude, Pa = %0.1f N/m^2 \"%Pa\n",
      "Ed=2*pi**2*n**2*p*A**2 \n",
      "print \"Energy density, Ed = %0.1e J/m^3 \" %Ed\n",
      "Ev=Ed*v \n",
      "print \"Energy flux, Ev = %0.2f J/m^2-s \" %Ev"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "Pressure amplitude, Pa = 13.8 N/m^2 \n",
        "Energy density, Ed = 6.4e-04 J/m^3 \n",
        "Energy flux, Ev = 0.22 J/m^2-s \n"
       ]
      }
     ],
     "prompt_number": 3
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Example 2, page 381"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "# Pressure \n",
      "#given data :\n",
      "gama=1.4 \n",
      "u=10**-3 # in m/s\n",
      "v=340 # in m/s\n",
      "P=10**5 # in N/m**2\n",
      "p=gama*P*u/v \n",
      "print \"The pressure, p = %0.2f N/m^2 \" %p"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "The pressure, p = 0.41 N/m^2 \n"
       ]
      }
     ],
     "prompt_number": 4
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Example 3, page 381"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "from math import sqrt\n",
      "# The amplitude \n",
      "#given data :\n",
      "n=350 # in Hz\n",
      "v=330 # in m/s\n",
      "p=1.293 # in kg/m**3\n",
      "I=1*10**-6 # in W/m**2\n",
      "A=sqrt(I/(2*pi*n**2*p*v)) \n",
      "print \"The amplitude of wave, A = %0.2e m \" %A"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "The amplitude of wave, A = 5.52e-08 m \n"
       ]
      }
     ],
     "prompt_number": 5
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Example 4, page 381"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "# Velocity, Amplitude of pressure and particle velocity amplitude\n",
      "#given data :\n",
      "gama=1.4 \n",
      "P=1.013*10**5 \n",
      "p1=1.29 # in kg/m**3\n",
      "A=2.5*10**-7 # in m\n",
      "v=sqrt(gama*P/p1) \n",
      "print \"The velocity, v = %0.1f m/s  \" %v\n",
      "n=1000 # in Hz\n",
      "lamda=v/n \n",
      "print \"Wavelength, lamda = %0.4f m \" %lamda\n",
      "p=p1*v*2*pi*n*A \n",
      "print \"Amplitude of pressure, p = %0.2f N/m^2 \" % p\n",
      "u=2*pi*n*A \n",
      "print \"Particle velocity amplitude, u = %0.2e m/s \" %u"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "The velocity, v = 331.6 m/s  \n",
        "Wavelength, lamda = 0.3316 m \n",
        "Amplitude of pressure, p = 0.67 N/m^2 \n",
        "Particle velocity amplitude, u = 1.57e-03 m/s \n"
       ]
      }
     ],
     "prompt_number": 9
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Example 5, page 382"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "from math import pi\n",
      "# Amplitude\n",
      "#given data :\n",
      "v=(1/3)*10**3 # in m/s\n",
      "p=1.25 # in kg/m**3\n",
      "E=v**2*p \n",
      "n=10**4 # in rad/sec\n",
      "print \"Bulk modulus of medium, E = %0.2e N/m^2\" %E\n",
      "I=10**-12 # in W/m**2\n",
      "A=sqrt(I/(2*pi**2*n**2*p*v)) \n",
      "print \"Amplitude of wave, A = %0.2e m  \" %A\n",
      "P=sqrt(2*I*p*v) \n",
      "print \"Pressure amplitude, P = %0.2e N/m^2 \" %P\n",
      "# answer A and E is wrong in textbook"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "Bulk modulus of medium, E = 1.39e+05 N/m^2\n",
        "Amplitude of wave, A = 1.10e-12 m  \n",
        "Pressure amplitude, P = 2.89e-05 N/m^2 \n"
       ]
      }
     ],
     "prompt_number": 13
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Example 6, page 383"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "from math import sqrt\n",
      "# Root mean squre velocity\n",
      "#given data :\n",
      "vs=330 # in m/s\n",
      "gama=1.41 \n",
      "c=round(sqrt(3/gama)*vs) \n",
      "print \"The root mean square velocity of modulus, c = %0.f m/s \"%c"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "The root mean square velocity of modulus, c = 481 m/s \n"
       ]
      }
     ],
     "prompt_number": 15
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Example 7, page 383"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "# Acoustic power entering\n",
      "#given data :\n",
      "A=1*2 # in m**2\n",
      "a=80 # in dB\n",
      "I0=10**-12 # in W/m**2\n",
      "IbyI0=10**(80/10) \n",
      "I=I0*IbyI0 \n",
      "Ape=I*A \n",
      "print \"Acoustic power entering the room = %0.e Watt  \" %Ape"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "Acoustic power entering the room = 2e-04 Watt  \n"
       ]
      }
     ],
     "prompt_number": 16
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Example 8, page 384"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "from math import log10\n",
      "# Acoustic intensity level\n",
      "#given data :\n",
      "Pr=3 # in W\n",
      "r=15 # in m\n",
      "I=Pr/(4*pi*r**2) # in W/m**2\n",
      "I0=10**-12 # in W/m**2\n",
      "L=round(10*log10(I/I0)) \n",
      "print \"Acoustic intensity level, L = %0.f dB \" %L"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "Acoustic intensity level, L = 90 dB \n"
       ]
      }
     ],
     "prompt_number": 18
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Example 9, page 391"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "# frequency\n",
      "n2=200 #second**-1\n",
      "l21=2 #\n",
      "f=l21*n2 #\n",
      "print \"Frequency = %0.f second^-1  \" %f"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "Frequency = 400 second^-1  \n"
       ]
      }
     ],
     "prompt_number": 19
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Example 10, page 391"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "# length\n",
      "l1=66 #cm\n",
      "v=330 #m/s\n",
      "nbs=5 #beats/sec\n",
      "x=(2*(v-(nbs*2*l1*10**-2))/(v*2*l1*10**-2)) #\n",
      "l2=1/x #cm\n",
      "print \"Length = %0.1f cm  \"%(l2*100)"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "Length = 67.3 cm  \n"
       ]
      }
     ],
     "prompt_number": 21
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Example 11, page 392"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "# length\n",
      "f=110 #Hz\n",
      "v=330 #m/s\n",
      "l=v/(2*f) #m\n",
      "print \"Fundamental frequency = %0.f Hz\" %f\n",
      "print \"Length = %0.1f m\" %l"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "Fundamental frequency = 110 Hz\n",
        "Length = 1.5 m\n"
       ]
      }
     ],
     "prompt_number": 22
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Example 12, page 392"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "# equation,frequency,amplitude ,wavelength and distance\n",
      "#y=6*(sin(2*pi*x)/6)*cos(160*pi*t) #given equation\n",
      "a=3 #cm\n",
      "T=(2*pi)/(160*pi) #sec\n",
      "h=((2*pi*6)/(2*pi)) #cm\n",
      "print \"wave equation is 3*sin((160*pi*t)+(2*pi*x)/6)\"\n",
      "print \"Amplitude = %0.2f cm \" %a\n",
      "print \"Frequency = %0.2f Hz  \" %(1/T)\n",
      "print h,\"wavelength is,(cm)=\"\n",
      "db=h/2 #\n",
      "print \"Distance between consecutive antinodes = %0.2f cm\" %db"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "wave equation is 3*sin((160*pi*t)+(2*pi*x)/6)\n",
        "Amplitude = 3.00 cm \n",
        "Frequency = 80.00 Hz  \n",
        "6.0 wavelength is,(cm)=\n",
        "Distance between consecutive antinodes = 3.00 cm\n"
       ]
      }
     ],
     "prompt_number": 23
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Example 13, page 393"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "from math import cos, pi\n",
      "# length,amlitude,pressure\n",
      "f=440 #Hz\n",
      "v=330 #m/s\n",
      "l=((5*v)/(4*f))*100 #cm\n",
      "print \"Length, L = %0.2f cm \" %l"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "Length, L = 93.75 cm \n"
       ]
      }
     ],
     "prompt_number": 27
    }
   ],
   "metadata": {}
  }
 ]
}