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Diffstat (limited to 'Engineering_Physics/Chapter18_1.ipynb')
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diff --git a/Engineering_Physics/Chapter18_1.ipynb b/Engineering_Physics/Chapter18_1.ipynb deleted file mode 100755 index 0a7b2021..00000000 --- a/Engineering_Physics/Chapter18_1.ipynb +++ /dev/null @@ -1,294 +0,0 @@ -{ - "metadata": { - "name": "", - "signature": "sha256:3bec68600cdf231538bf44a09963d76f89f72c71634091075e5c4136c75bb4a6" - }, - "nbformat": 3, - "nbformat_minor": 0, - "worksheets": [ - { - "cells": [ - { - "cell_type": "heading", - "level": 1, - "metadata": {}, - "source": [ - "18: Acoustics of Buildings" - ] - }, - { - "cell_type": "heading", - "level": 2, - "metadata": {}, - "source": [ - "Example number 18.1, Page number 361" - ] - }, - { - "cell_type": "code", - "collapsed": false, - "input": [ - " \n", - "#importing modules\n", - "import math\n", - "from __future__ import division\n", - "\n", - "#Variable declaration\n", - "r = 200; #Distance of the point of reduction from the source(m)\n", - "I_0 = 10**-12; #Final intensity of sound(W/m**2)\n", - "I_f = 60; #Intensity gain of sound at the point of reduction(dB)\n", - "\n", - "#Calculation\n", - "#As A_I = 10*log10(I/I_0), solving for I\n", - "I = I_0*10**(I_f/10); #Initial Intensity of sound(W/m**2)\n", - "P = 4*math.pi*r**2*I; #Output power of the sound source(W)\n", - "P = math.ceil(P*100)/100; #rounding off the value of P to 2 decimals\n", - "\n", - "#Result\n", - "print \"The output power of the sound source is\",P, \"W\"" - ], - "language": "python", - "metadata": {}, - "outputs": [ - { - "output_type": "stream", - "stream": "stdout", - "text": [ - "The output power of the sound source is 0.51 W\n" - ] - } - ], - "prompt_number": 1 - }, - { - "cell_type": "heading", - "level": 2, - "metadata": {}, - "source": [ - "Example number 18.2, Page number 361" - ] - }, - { - "cell_type": "code", - "collapsed": false, - "input": [ - " \n", - "#importing modules\n", - "import math\n", - "from __future__ import division\n", - "import numpy as np\n", - "\n", - "#Variable declaration\n", - "I1 = 1; #For simplicity assume first intensity level to be unity(W/m**2)\n", - "\n", - "#Calculation\n", - "I2 = 2*I1; #Intensity level after doubling(W/m**2)\n", - "dA_I = 10*np.log10(I2/I1); #Difference in gain level(dB)\n", - "\n", - "#Result\n", - "print \"The sound intensity level is increased by\",int(dA_I), \"dB\"" - ], - "language": "python", - "metadata": {}, - "outputs": [ - { - "output_type": "stream", - "stream": "stdout", - "text": [ - "The sound intensity level is increased by 3 dB\n" - ] - } - ], - "prompt_number": 3 - }, - { - "cell_type": "heading", - "level": 2, - "metadata": {}, - "source": [ - "Example number 18.3, Page number 361" - ] - }, - { - "cell_type": "code", - "collapsed": false, - "input": [ - " \n", - "#importing modules\n", - "import math\n", - "from __future__ import division\n", - "\n", - "#Variable declaration\n", - "V = 8000; #Volume of the hall(m**3)\n", - "T = 1.5; #Reverbration time of the hall(s)\n", - "\n", - "#Calculation\n", - "alpha_s = 0.167*V/T; #Sabine Formula giving total absorption of sound in the hall(OWU)\n", - "alpha_s = math.ceil(alpha_s*10)/10; #rounding off the value of alpha_s to 1 decimal\n", - "\n", - "#Result\n", - "print \"The total absorption of sound in the hall is\",alpha_s, \"OWU\"\n" - ], - "language": "python", - "metadata": {}, - "outputs": [ - { - "output_type": "stream", - "stream": "stdout", - "text": [ - "The total absorption of sound in the hall is 890.7 OWU\n" - ] - } - ], - "prompt_number": 4 - }, - { - "cell_type": "heading", - "level": 2, - "metadata": {}, - "source": [ - "Example number 18.4, Page number 362" - ] - }, - { - "cell_type": "code", - "collapsed": false, - "input": [ - "\n", - "#importing modules\n", - "import math\n", - "from __future__ import division\n", - "\n", - "#Variable declaration\n", - "V = 25*20*8; #Volume of the hall(m**3)\n", - "T = 4; #Reverbration time of the hall(s)\n", - "\n", - "#Calculation\n", - "S = 2*(25*20+25*8+20*8); #Total surface area of the hall(m**2)\n", - "alpha = 0.167*V/(T*S); #Sabine Formule giving total absorption in the hall(OWU)\n", - "alpha = math.ceil(alpha*10**4)/10**4; #rounding off the value of alpha to 4 decimals\n", - "\n", - "#Result\n", - "print \"The average absorption coefficient of the surfaces is\",alpha, \"OWU/m**2\"\n" - ], - "language": "python", - "metadata": {}, - "outputs": [ - { - "output_type": "stream", - "stream": "stdout", - "text": [ - "The average absorption coefficient of the surfaces is 0.0971 OWU/m**2\n" - ] - } - ], - "prompt_number": 5 - }, - { - "cell_type": "heading", - "level": 2, - "metadata": {}, - "source": [ - "Example number 18.5, Page number 362" - ] - }, - { - "cell_type": "code", - "collapsed": false, - "input": [ - " \n", - "#importing modules\n", - "import math\n", - "from __future__ import division\n", - "\n", - "#Variable declaration\n", - "V = 475; #Volume of the hall(m**3)\n", - "A_f = 100; #Area of the floor(m**2)\n", - "A_c = 100; #Area of the ceiling(m**2)\n", - "A_w = 200; #Area of the wall(m**2)\n", - "alpha_w = 0.025; #Absorption coefficients of the wall(OWU/m**2)\n", - "alpha_c = 0.02; #Absorption coefficients of the ceiling(OWU/m**2)\n", - "alpha_f = 0.55; #Absorption coefficients of the floor(OWU/m**2)\n", - "\n", - "#Calculation\n", - "alpha_s = (A_w*alpha_w)+(A_c*alpha_c)+(A_f*alpha_f); \n", - "T = 0.167*V/alpha_s; #Sabine Formula for reverbration time(s)\n", - "T = math.ceil(T*100)/100; #rounding off the value of T to 2 decimals\n", - "\n", - "#Result\n", - "print \"The reverbration time for the hall is\",T, \"s\"\n" - ], - "language": "python", - "metadata": {}, - "outputs": [ - { - "output_type": "stream", - "stream": "stdout", - "text": [ - "The reverbration time for the hall is 1.28 s\n" - ] - } - ], - "prompt_number": 6 - }, - { - "cell_type": "heading", - "level": 2, - "metadata": {}, - "source": [ - "Example number 18.6, Page number 362" - ] - }, - { - "cell_type": "code", - "collapsed": false, - "input": [ - " \n", - "#importing modules\n", - "import math\n", - "from __future__ import division\n", - "\n", - "#Variable declaration\n", - "I0 = 1; #For simplicity assume initial sound intensity to be unity(W/m**2)\n", - "A_I1 = 80; #First intensity gain of sound(dB)\n", - "A_I2 = 70; #Second intensity gain of sound(dB)\n", - "\n", - "#Calculation\n", - "#As A_I = 10*log10(I/I_0), solving for I1 and I2\n", - "I1 = 10**(A_I1/10)*I0; #First intensity of sound(W/m**2)\n", - "I2 = 10**(A_I2/10)*I0; #Second intensity of sound(W/m**2)\n", - "I = I1 + I2; #Resultant intensity level of sound(W/m**2)\n", - "A_I = 10*np.log10(I/I0); #Intensity gain of resultant sound(dB)\n", - "A_I = math.ceil(A_I*10**3)/10**3; #rounding off the value of A_I to 3 decimals\n", - "\n", - "#Result\n", - "print \"The intensity gain of resultant sound is\",A_I, \"dB\"\n", - "\n", - "#answer given in the book is wrong" - ], - "language": "python", - "metadata": {}, - "outputs": [ - { - "output_type": "stream", - "stream": "stdout", - "text": [ - "The intensity gain of resultant sound is 80.414 dB\n" - ] - } - ], - "prompt_number": 7 - }, - { - "cell_type": "code", - "collapsed": false, - "input": [], - "language": "python", - "metadata": {}, - "outputs": [] - } - ], - "metadata": {} - } - ] -}
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