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Diffstat (limited to 'Engineering_Physics_Aruldhas/Chapter18_1.ipynb')
| -rw-r--r-- | Engineering_Physics_Aruldhas/Chapter18_1.ipynb | 188 |
1 files changed, 167 insertions, 21 deletions
diff --git a/Engineering_Physics_Aruldhas/Chapter18_1.ipynb b/Engineering_Physics_Aruldhas/Chapter18_1.ipynb index aca20375..553fe50f 100644 --- a/Engineering_Physics_Aruldhas/Chapter18_1.ipynb +++ b/Engineering_Physics_Aruldhas/Chapter18_1.ipynb @@ -1,6 +1,7 @@ { "metadata": { - "name": "Chapter18" + "name": "", + "signature": "sha256:c2afbaf4a700c8f5f48d1946053d882d86bb1b0270a68b2bbedc639668ea43be" }, "nbformat": 3, "nbformat_minor": 0, @@ -11,25 +12,51 @@ "cell_type": "heading", "level": 1, "metadata": {}, - "source": "18: Acoustics of Buildings" + "source": [ + "18: Acoustics of Buildings" + ] }, { "cell_type": "heading", "level": 2, "metadata": {}, - "source": "Example number 18.1, Page number 361" + "source": [ + "Example number 18.1, Page number 361" + ] }, { "cell_type": "code", "collapsed": false, - "input": "#To calculate the output power of the sound source\n\n#importing modules\nimport math\nfrom __future__ import division\n\n#Variable declaration\nr = 200; #Distance of the point of reduction from the source(m)\nI_0 = 10**-12; #Final intensity of sound(W/m**2)\nI_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\nI = I_0*10**(I_f/10); #Initial Intensity of sound(W/m**2)\nP = 4*math.pi*r**2*I; #Output power of the sound source(W)\nP = math.ceil(P*100)/100; #rounding off the value of P to 2 decimals\n\n#Result\nprint \"The output power of the sound source is\",P, \"W\"", + "input": [ + "\n", + "\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" + "text": [ + "The output power of the sound source is 0.51 W\n" + ] } ], "prompt_number": 1 @@ -38,19 +65,40 @@ "cell_type": "heading", "level": 2, "metadata": {}, - "source": "Example number 18.2, Page number 361" + "source": [ + "Example number 18.2, Page number 361" + ] }, { "cell_type": "code", "collapsed": false, - "input": "#To calculate the change in sound level\n\n#importing modules\nimport math\nfrom __future__ import division\nimport numpy as np\n\n#Variable declaration\nI1 = 1; #For simplicity assume first intensity level to be unity(W/m**2)\n\n#Calculation\nI2 = 2*I1; #Intensity level after doubling(W/m**2)\ndA_I = 10*np.log10(I2/I1); #Difference in gain level(dB)\n\n#Result\nprint \"The sound intensity level is increased by\",int(dA_I), \"dB\"", + "input": [ + "\n", + "\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" + "text": [ + "The sound intensity level is increased by 3 dB\n" + ] } ], "prompt_number": 3 @@ -59,19 +107,39 @@ "cell_type": "heading", "level": 2, "metadata": {}, - "source": "Example number 18.3, Page number 361" + "source": [ + "Example number 18.3, Page number 361" + ] }, { "cell_type": "code", "collapsed": false, - "input": "#To calculate the total absorption of sound in the hall\n\n#importing modules\nimport math\nfrom __future__ import division\n\n#Variable declaration\nV = 8000; #Volume of the hall(m**3)\nT = 1.5; #Reverbration time of the hall(s)\n\n#Calculation\nalpha_s = 0.167*V/T; #Sabine Formula giving total absorption of sound in the hall(OWU)\nalpha_s = math.ceil(alpha_s*10)/10; #rounding off the value of alpha_s to 1 decimal\n\n#Result\nprint \"The total absorption of sound in the hall is\",alpha_s, \"OWU\"\n", + "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" + "text": [ + "The total absorption of sound in the hall is 890.7 OWU\n" + ] } ], "prompt_number": 4 @@ -80,19 +148,42 @@ "cell_type": "heading", "level": 2, "metadata": {}, - "source": "Example number 18.4, Page number 362" + "source": [ + "Example number 18.4, Page number 362" + ] }, { "cell_type": "code", "collapsed": false, - "input": "#To calculate the average absorption coefficient of the surfaces\n\n#importing modules\nimport math\nfrom __future__ import division\n\n#Variable declaration\nV = 25*20*8; #Volume of the hall(m**3)\nT = 4; #Reverbration time of the hall(s)\n\n#Calculation\nS = 2*(25*20+25*8+20*8); #Total surface area of the hall(m**2)\nalpha = 0.167*V/(T*S); #Sabine Formule giving total absorption in the hall(OWU)\nalpha = math.ceil(alpha*10**4)/10**4; #rounding off the value of alpha to 4 decimals\n\n#Result\nprint \"The average absorption coefficient of the surfaces is\",alpha, \"OWU/m**2\"\n", + "input": [ + "\n", + "\n", + "\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" + "text": [ + "The average absorption coefficient of the surfaces is 0.0971 OWU/m**2\n" + ] } ], "prompt_number": 5 @@ -101,19 +192,46 @@ "cell_type": "heading", "level": 2, "metadata": {}, - "source": "Example number 18.5, Page number 362" + "source": [ + "Example number 18.5, Page number 362" + ] }, { "cell_type": "code", "collapsed": false, - "input": "#To calculate the reverbration time for the hall\n\n#importing modules\nimport math\nfrom __future__ import division\n\n#Variable declaration\nV = 475; #Volume of the hall(m**3)\nA_f = 100; #Area of the floor(m**2)\nA_c = 100; #Area of the ceiling(m**2)\nA_w = 200; #Area of the wall(m**2)\nalpha_w = 0.025; #Absorption coefficients of the wall(OWU/m**2)\nalpha_c = 0.02; #Absorption coefficients of the ceiling(OWU/m**2)\nalpha_f = 0.55; #Absorption coefficients of the floor(OWU/m**2)\n\n#Calculation\nalpha_s = (A_w*alpha_w)+(A_c*alpha_c)+(A_f*alpha_f); \nT = 0.167*V/alpha_s; #Sabine Formula for reverbration time(s)\nT = math.ceil(T*100)/100; #rounding off the value of T to 2 decimals\n\n#Result\nprint \"The reverbration time for the hall is\",T, \"s\"\n", + "input": [ + "\n", + "\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" + "text": [ + "The reverbration time for the hall is 1.28 s\n" + ] } ], "prompt_number": 6 @@ -122,19 +240,47 @@ "cell_type": "heading", "level": 2, "metadata": {}, - "source": "Example number 18.6, Page number 362" + "source": [ + "Example number 18.6, Page number 362" + ] }, { "cell_type": "code", "collapsed": false, - "input": "#To calculate the reverbration time for the hall\n\n#importing modules\nimport math\nfrom __future__ import division\n\n#Variable declaration\nI0 = 1; #For simplicity assume initial sound intensity to be unity(W/m**2)\nA_I1 = 80; #First intensity gain of sound(dB)\nA_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\nI1 = 10**(A_I1/10)*I0; #First intensity of sound(W/m**2)\nI2 = 10**(A_I2/10)*I0; #Second intensity of sound(W/m**2)\nI = I1 + I2; #Resultant intensity level of sound(W/m**2)\nA_I = 10*np.log10(I/I0); #Intensity gain of resultant sound(dB)\nA_I = math.ceil(A_I*10**3)/10**3; #rounding off the value of A_I to 3 decimals\n\n#Result\nprint \"The intensity gain of resultant sound is\",A_I, \"dB\"\n\n#answer given in the book is wrong", + "input": [ + "\n", + "\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" + "text": [ + "The intensity gain of resultant sound is 80.414 dB\n" + ] } ], "prompt_number": 7 @@ -142,7 +288,7 @@ { "cell_type": "code", "collapsed": false, - "input": "", + "input": [], "language": "python", "metadata": {}, "outputs": [] |