{ "metadata": { "name": "", "signature": "sha256:dcc4019ef1c15d21354e91688bcf3d6888473d71d7b26b6c010e7b08e8a6177f" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "heading", "level": 1, "metadata": {}, "source": [ "5: Ultrasonics" ] }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example number 5.1, Page number 23" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#importing modules\n", "import math\n", "from __future__ import division\n", "\n", "#Variable declaration\n", "t=1*10**-3; #thickness of crystal(m)\n", "rho=2650; #density of quartz(kg/m**3)\n", "Y=7.9*10**10; #young's modulus(N/m**2)\n", "p=1;\n", "\n", "#Calculation\n", "f=(p/(2*t))*math.sqrt(Y/rho); #fundamental frequency(Hz)\n", "\n", "#Result\n", "print \"fundamental frequency is\",round(f/10**6,5),\"*10**6 Hz\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "fundamental frequency is 2.72999 *10**6 Hz\n" ] } ], "prompt_number": 4 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example number 5.2, Page number 23" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#importing modules\n", "import math\n", "from __future__ import division\n", "\n", "#Variable declaration\n", "t=5*10**-3; #length of crystal(m)\n", "Y=7.9*10**10; #young's modulus(N/m**2)\n", "p1=1;\n", "p2=2;\n", "rho=2650; #density of quartz(kg/m**3)\n", "\n", "#Calculation\n", "f1=(p1/(2*t))*math.sqrt(Y/rho); #fundamental frequency(Hz)\n", "f2=(p2/(2*t))*math.sqrt(Y/rho); #frequency of 1st overtone(Hz)\n", "\n", "#Result\n", "print \"fundamental frequency is\",round(f1/10**5,2),\"*10**5 Hz\"\n", "print \"frequency of 1st overtone is\",round(f2/10**6,3),\"*10**6 Hz\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "fundamental frequency is 5.46 *10**5 Hz\n", "frequency of 1st overtone is 1.092 *10**6 Hz\n" ] } ], "prompt_number": 9 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example number 5.3, Page number 24" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#importing modules\n", "import math\n", "from __future__ import division\n", "\n", "#Variable declaration\n", "u=5000; #velocity of sound in steel(m/s)\n", "f=50*10**3; #difference between frequencies(Hz)\n", "\n", "#Calculation\n", "d=u/(2*f); #thickness of steel plate(m)\n", "\n", "#Result\n", "print \"thickness of steel plate is\",d,\"m\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "thickness of steel plate is 0.05 m\n" ] } ], "prompt_number": 10 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example number 5.4, Page number 25" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#importing modules\n", "import math\n", "from __future__ import division\n", "\n", "#Variable declaration\n", "t=1; #assume\n", "f1=(2.87*10**3)/t; #fundamental frequency(Hz)\n", "f=1200*10**3; #frequency(Hz)\n", "rho=2660; #density of quartz(kg/m**3)\n", "\n", "#Calculation\n", "Y=rho*(f1*2*t)**2; #young's modulus(N/m**2)\n", "t1=(1/(2*f))*math.sqrt(Y/rho); #thickness of crystal(m)\n", "\n", "#Result\n", "print \"young's modulus is\",round(Y/10**10,3),\"*10**10 N/m**2\"\n", "print \"thickness of crystal is\",round(t1*10**3,2),\"*10**-3 m\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "young's modulus is 8.764 *10**10 N/m**2\n", "thickness of crystal is 2.39 *10**-3 m\n" ] } ], "prompt_number": 18 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example number 5.5, Page number 26" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#importing modules\n", "import math\n", "from __future__ import division\n", "\n", "#Variable declaration\n", "f=7*10**6; #ultrasonic frequency(Hz)\n", "theta=45; #transducer angle(degrees)\n", "v=1.5; #blood velocity(m/s)\n", "U=1500; #ultrasonic velocity(m/s)\n", "\n", "#Calculation\n", "theta=theta*(math.pi/180); #transducer angle(radian)\n", "deltaf=2*f*v*math.cos(theta)/U; #audio frequency(Hz)\n", "\n", "#Result\n", "print \"audio frequency is\",round(deltaf/10**3),\"kHz\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "audio frequency is 10.0 kHz\n" ] } ], "prompt_number": 22 } ], "metadata": {} } ] }