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diff --git a/Engineering_Physics_by_Rajendran/Chapter4.ipynb b/Engineering_Physics_by_Rajendran/Chapter4.ipynb new file mode 100755 index 00000000..be4a2831 --- /dev/null +++ b/Engineering_Physics_by_Rajendran/Chapter4.ipynb @@ -0,0 +1,451 @@ +{
+ "metadata": {
+ "name": "",
+ "signature": "sha256:3f5941b661a8515cae38219efa7050e771c862dd351401d57b16c57806506e2a"
+ },
+ "nbformat": 3,
+ "nbformat_minor": 0,
+ "worksheets": [
+ {
+ "cells": [
+ {
+ "cell_type": "heading",
+ "level": 1,
+ "metadata": {},
+ "source": [
+ "4: Acoustics"
+ ]
+ },
+ {
+ "cell_type": "heading",
+ "level": 2,
+ "metadata": {},
+ "source": [
+ "Example number 4.1, Page number 24"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "collapsed": false,
+ "input": [
+ "#importing modules\n",
+ "import math\n",
+ "from __future__ import division\n",
+ "import numpy as np\n",
+ "\n",
+ "#Variable declaration\n",
+ "I1=10**-12; #intensity(W/m**2)\n",
+ "I2=0.1; #intensity of sound(W/m**2)\n",
+ "\n",
+ "#Calculation\n",
+ "beta=10*np.log10(I2/I1); #intensity level(dB) \n",
+ "\n",
+ "#Result\n",
+ "print \"intensity level is\",beta,\"dB\""
+ ],
+ "language": "python",
+ "metadata": {},
+ "outputs": [
+ {
+ "output_type": "stream",
+ "stream": "stdout",
+ "text": [
+ "intensity level is 110.0 dB\n"
+ ]
+ }
+ ],
+ "prompt_number": 3
+ },
+ {
+ "cell_type": "heading",
+ "level": 2,
+ "metadata": {},
+ "source": [
+ "Example number 4.2, Page number 24"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "collapsed": false,
+ "input": [
+ "#importing modules\n",
+ "import math\n",
+ "from __future__ import division\n",
+ "import numpy as np\n",
+ "\n",
+ "#Variable declaration\n",
+ "I1=10**-12; #intensity(W/m**2)\n",
+ "I2=10**-4; #intensity of sound(W/m**2)\n",
+ "\n",
+ "#Calculation\n",
+ "beta=10*np.log10(I2/I1); #relative sound intensity(dB) \n",
+ "\n",
+ "#Result\n",
+ "print \"relative sound intensity is\",beta,\"dB\""
+ ],
+ "language": "python",
+ "metadata": {},
+ "outputs": [
+ {
+ "output_type": "stream",
+ "stream": "stdout",
+ "text": [
+ "relative sound intensity is 80.0 dB\n"
+ ]
+ }
+ ],
+ "prompt_number": 6
+ },
+ {
+ "cell_type": "heading",
+ "level": 2,
+ "metadata": {},
+ "source": [
+ "Example number 4.3, Page number 25"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "collapsed": false,
+ "input": [
+ "#importing modules\n",
+ "import math\n",
+ "from __future__ import division\n",
+ "import numpy as np\n",
+ "\n",
+ "#Variable declaration\n",
+ "I2byI1=2; #intensity ratio\n",
+ "\n",
+ "#Calculation\n",
+ "beta=10*np.log10(I2byI1); #increase in sound intensity level(dB) \n",
+ "\n",
+ "#Result\n",
+ "print \"increase in sound intensity level is\",round(beta,2),\"dB\""
+ ],
+ "language": "python",
+ "metadata": {},
+ "outputs": [
+ {
+ "output_type": "stream",
+ "stream": "stdout",
+ "text": [
+ "increase in sound intensity level is 3.01 dB\n"
+ ]
+ }
+ ],
+ "prompt_number": 10
+ },
+ {
+ "cell_type": "heading",
+ "level": 2,
+ "metadata": {},
+ "source": [
+ "Example number 4.4, Page number 25"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "collapsed": false,
+ "input": [
+ "#importing modules\n",
+ "import math\n",
+ "from __future__ import division\n",
+ "import numpy as np\n",
+ "\n",
+ "#Variable declaration\n",
+ "P=3.14; #power radiated(W)\n",
+ "r=10; #radius(m)\n",
+ "I11=100; #intensity(W/m**2)\n",
+ "I12=1; #intensity(W/m**2)\n",
+ "I13=10**-12; #intensity(W/m**2)\n",
+ "\n",
+ "#Calculation\n",
+ "I2=P/(4*math.pi*r**2); #intensity of sound(W/m**2)\n",
+ "beta1=10*np.log10(I2/I11); #relative intensity(dB) \n",
+ "beta2=10*np.log10(I2/I12); #relative intensity(dB) \n",
+ "beta3=10*np.log10(I2/I13); #relative intensity(dB) \n",
+ "\n",
+ "#Result\n",
+ "print \"relative intensity with respect to 100W/m**2 is\",round(beta1,4),\"dB\"\n",
+ "print \"relative intensity with respect to 1W/m**2 is\",round(beta2,4),\"dB\"\n",
+ "print \"relative intensity with respect to 10**-12W/m**2 is\",round(beta3,3),\"dB\""
+ ],
+ "language": "python",
+ "metadata": {},
+ "outputs": [
+ {
+ "output_type": "stream",
+ "stream": "stdout",
+ "text": [
+ "relative intensity with respect to 100W/m**2 is -46.0228 dB\n",
+ "relative intensity with respect to 1W/m**2 is -26.0228 dB\n",
+ "relative intensity with respect to 10**-12W/m**2 is 93.977 dB\n"
+ ]
+ }
+ ],
+ "prompt_number": 13
+ },
+ {
+ "cell_type": "heading",
+ "level": 2,
+ "metadata": {},
+ "source": [
+ "Example number 4.5, Page number 26"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "collapsed": false,
+ "input": [
+ "#importing modules\n",
+ "import math\n",
+ "from __future__ import division\n",
+ "import numpy as np\n",
+ "\n",
+ "#Variable declaration\n",
+ "P=1.5; #power radiated(J/s)\n",
+ "r=20; #radius(m)\n",
+ "I1=10**-12; #intensity level of sound(W/m**2)\n",
+ "\n",
+ "#Calculation\n",
+ "I2=P/(4*math.pi*r**2); #intensity of sound(W/m**2)\n",
+ "beta=10*np.log10(I2/I1); #intensity level(dB) \n",
+ "\n",
+ "#Result\n",
+ "print \"intensity level of sound is\",round(beta,1),\"dB\""
+ ],
+ "language": "python",
+ "metadata": {},
+ "outputs": [
+ {
+ "output_type": "stream",
+ "stream": "stdout",
+ "text": [
+ "intensity level of sound is 84.7 dB\n"
+ ]
+ }
+ ],
+ "prompt_number": 15
+ },
+ {
+ "cell_type": "heading",
+ "level": 2,
+ "metadata": {},
+ "source": [
+ "Example number 4.6, Page number 27"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "collapsed": false,
+ "input": [
+ "#importing modules\n",
+ "import math\n",
+ "from __future__ import division\n",
+ "\n",
+ "#Variable declaration\n",
+ "beta1=80; #intensity level of sound(dB)\n",
+ "\n",
+ "#Calculation\n",
+ "\n",
+ "\n",
+ "#Result\n",
+ "print \" \""
+ ],
+ "language": "python",
+ "metadata": {},
+ "outputs": [
+ {
+ "output_type": "stream",
+ "stream": "stdout",
+ "text": [
+ " \n"
+ ]
+ }
+ ],
+ "prompt_number": 16
+ },
+ {
+ "cell_type": "heading",
+ "level": 2,
+ "metadata": {},
+ "source": [
+ "Example number 4.7, Page number 28"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "collapsed": false,
+ "input": [
+ "#importing modules\n",
+ "import math\n",
+ "from __future__ import division\n",
+ "\n",
+ "#Variable declaration\n",
+ "V=1500; #volume of hall(m**3)\n",
+ "sigma_a1s=100; #absorption of sound by hall(sabine)\n",
+ "sigma_a2s=100; #absorption of sound by audience(sabine)\n",
+ "\n",
+ "#Calculation\n",
+ "A=sigma_a1s+sigma_a2s; #total absorption(sabine)\n",
+ "t1=0.16*V/sigma_a1s; #reverberation time of hall when room is empty(s)\n",
+ "t2=0.16*V/(sigma_a1s+sigma_a2s); #reverberation time of hall when room is filled(s)\n",
+ "t=t1-t2; #change in reverberation time(s)\n",
+ "\n",
+ "#Result\n",
+ "print \"when the room is filled, reverberation time is reduced to\",t,\"s\""
+ ],
+ "language": "python",
+ "metadata": {},
+ "outputs": [
+ {
+ "output_type": "stream",
+ "stream": "stdout",
+ "text": [
+ "when the room is filled, reverberation time is reduced to 1.2 s\n"
+ ]
+ }
+ ],
+ "prompt_number": 17
+ },
+ {
+ "cell_type": "heading",
+ "level": 2,
+ "metadata": {},
+ "source": [
+ "Example number 4.8, Page number 28"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "collapsed": false,
+ "input": [
+ "#importing modules\n",
+ "import math\n",
+ "from __future__ import division\n",
+ "\n",
+ "#Variable declaration\n",
+ "V=1000; #volume of hall(m**3)\n",
+ "T=2; #reverberation time(s)\n",
+ "s=350; #area of sound absorbing surface(m**2)\n",
+ "\n",
+ "#Calculation\n",
+ "alpha=0.16*V/(T*s); #average absorption coefficient\n",
+ "\n",
+ "#Result\n",
+ "print \"average absorption coefficient is\",round(alpha,5)"
+ ],
+ "language": "python",
+ "metadata": {},
+ "outputs": [
+ {
+ "output_type": "stream",
+ "stream": "stdout",
+ "text": [
+ "average absorption coefficient is 0.22857\n"
+ ]
+ }
+ ],
+ "prompt_number": 19
+ },
+ {
+ "cell_type": "heading",
+ "level": 2,
+ "metadata": {},
+ "source": [
+ "Example number 4.9, Page number 29"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "collapsed": false,
+ "input": [
+ "#importing modules\n",
+ "import math\n",
+ "from __future__ import division\n",
+ "\n",
+ "#Variable declaration\n",
+ "V=2400; #volume of hall(m**3)\n",
+ "a1=500; #area of plaster ceiling(m**2)\n",
+ "s1=0.02; #coefficient of absorption of plaster ceiling\n",
+ "a2=600; #area of plaster walls(m**2)\n",
+ "s2=0.03; #coefficient of absorption of plaster walls\n",
+ "a3=500; #area of wood floor(m**2)\n",
+ "s3=0.06; #coefficient of absorption of wood floor\n",
+ "a4=20; #area of wood doors(m**2)\n",
+ "s4=0.06; #coefficient of absorption of wood doors\n",
+ "a5=400; #area of cushion seats(m**2)\n",
+ "s5=0.01; #coefficient of absorption of cushion seats\n",
+ "a6=200; #area of cane seats(m**2)\n",
+ "s6=0.01; #coefficient of absorption of cane seats \n",
+ "s=0.45; #absorption of each member(sabine)\n",
+ "\n",
+ "#Calculation\n",
+ "sigma_asE=(a1*s1)+(a2*s2)+(a3*s3)+(a4*s4)+(a5*s5)+(a6*s6); #total absorption when hall is empty(sabine)\n",
+ "TE=0.16*V/sigma_asE; #reverberation time when hall is empty(s)\n",
+ "sigma_asF=(a1*s1)+(a2*s2)+(a3*s3)+(a4*s4)+(a5*s)+(a6*s); #total absorption when hall is filled(sabine)\n",
+ "TF=0.16*V/sigma_asF; #reverberation time when hall is filled(s)\n",
+ "\n",
+ "#Result\n",
+ "print \"reverberation time when hall is empty is\",round(TE,4),\"s\"\n",
+ "print \"reverberation time when hall is filled is\",round(TF,3),\"s\""
+ ],
+ "language": "python",
+ "metadata": {},
+ "outputs": [
+ {
+ "output_type": "stream",
+ "stream": "stdout",
+ "text": [
+ "reverberation time when hall is empty is 5.8896 s\n",
+ "reverberation time when hall is filled is 1.166 s\n"
+ ]
+ }
+ ],
+ "prompt_number": 23
+ },
+ {
+ "cell_type": "heading",
+ "level": 2,
+ "metadata": {},
+ "source": [
+ "Example number 4.10, Page number 30"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "collapsed": false,
+ "input": [
+ "#importing modules\n",
+ "import math\n",
+ "from __future__ import division\n",
+ "import numpy as np\n",
+ "\n",
+ "#Variable declaration\n",
+ "I1=10**-12; #intensity(W/m**2)\n",
+ "I2=100; #intensity of sound(W/m**2)\n",
+ "\n",
+ "#Calculation\n",
+ "beta=10*np.log10(I2/I1); #intensity level of jet plane(dB) \n",
+ "\n",
+ "#Result\n",
+ "print \"intensity level of jet plane is\",beta,\"dB\""
+ ],
+ "language": "python",
+ "metadata": {},
+ "outputs": [
+ {
+ "output_type": "stream",
+ "stream": "stdout",
+ "text": [
+ "intensity level of jet plane is 140.0 dB\n"
+ ]
+ }
+ ],
+ "prompt_number": 25
+ }
+ ],
+ "metadata": {}
+ }
+ ]
+}
\ No newline at end of file |