{ "metadata": { "name": "Chapter4" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "heading", "level": 1, "metadata": {}, "source": [ "Chapter 4:The Wave Like Properties of Particles" ] }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 4.1 Page 101" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#initiation of variable\n", "from math import sqrt\n", "h=6.6*10**-34; # h(planck's constant)= 6.6*10^-34 \n", "m1= 10.0**3;v1=100.0; # for automobile\n", "\n", "#calculation\n", "w1= h/(m1*v1); # ['w'-wavelength in metre'm'-mass in Kg 'v'-velocity in metres/sec.] of the particles \n", "m2=10.0*(10**-3);v2= 500; # for bullet\n", "w2=h/(m2*v2);\n", "m3=(10.0**-9)*(10.0**-3); v3=1.0*10**-2;\n", "w3=h/(m3*v3);\n", "m4=9.1*10**-31;k=1*1.6*10**-19; # k- kinetic energy of the electron & using 1ev = 1.6*10^-19 joule\n", "p=sqrt(2.0*m4*k); # p=momentum of electron ;from K=1/2*m*v^2\n", "w4=h/p;\n", "hc=1240;pc=100 # In the extreme relativistc realm, K=E=pc; Given pc=100MeV,hc=1240MeV \n", "w5= hc/pc;\n", "\n", "#result\n", "print \"Wavelength of the automobile in m is\",w1;\n", "print \"Wavelength of the bullet in m is \",w2 ;\n", "print\"Wavelength of the smoke particle in m is\",w3 ;\n", "print \"Wavelength of the electron(1ev) in nm is\",round(w4*10**9,3) ;\n", "print \"Wavelength of the electron (100Mev) in fm is\",w5;" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Wavelength of the automobile in m is 6.6e-39\n", "Wavelength of the bullet in m is 1.32e-34\n", "Wavelength of the smoke particle in m is 6.6e-20\n", "Wavelength of the electron(1ev) in nm is 1.223\n", "Wavelength of the electron (100Mev) in fm is 12\n" ] } ], "prompt_number": 3 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 4.2 Page 113" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#initiation of variable\n", "from math import pi\n", "# w=wavelength; consider k=2*(pi/w); \n", "# differentiate k w.r.t w and replace del(k)/del(w) = 1 for equation.4.3\n", "# which gives del(w)= w^2 /(2*pi*del(x)), hence \n", "w=20; delx=200; # delx=200cm and w=20cm\n", "\n", "#calculation\n", "delw=(w**2)/(delx*2*pi);\n", "\n", "#result\n", "print \"Hence uncertainity in length in cm is\",round(delw,3);" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Hence uncertainity in length is in cm 0.318\n" ] } ], "prompt_number": 4 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 4.3 Page 114" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#initiation of variable\n", "from math import pi\n", "delt=1.0; #consider time interval of 1 sec\n", "delw=1/delt; # since delw*delt =1 from equation 4.4\n", "delf=0.01 #calculated accuracy is 0.01Hz\n", "\n", "#calculation\n", "delwc =2*pi*delf # delwc-claimed accuracy from w=2*pi*f\n", "\n", "#result\n", "print \"The minimum uncertainity calculated is 1rad/sec. The claimed accuracy in rad/sec is \\n\",round(delwc,3);\n", "print \"thus there is a reason to doubt the claim\"\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The minimum uncertainity calculated is 1rad/sec. The claimed accuracy is in rad/sec\n", "0.063\n", "thus there is a reason to doubt the claim\n" ] } ], "prompt_number": 6 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 4.4 Page 115" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#initiation of variable\n", "from math import pi\n", "m=9.11*10**-31;v=3.6*10**6; #'m','v' - mass an velocity of the electron in SI units\n", "h=1.05*10**-34; #planck's constant in SI\n", "p=m*v; #momentum\n", "delp=p*0.01; #due to 1% precision in p\n", "delx = h/delp; #uncertainity in position\n", "\n", "#result\n", "print \"Uncertainty in position in nm is\",round(delx*10**9,2);\n", "\n", "#partb\n", "print \"Since the motion is strictly along X-direction, its velocity in Y direction is absolutely zero.\\n So uncertainity in velocity along y is zero=> uncertainity in position along y is infinite. \\nSo nothing can be said about its position/motion along \"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Uncertainity in position in nm is 3.2\n", "Since the motion is strictly along X-direction, its velocity in Y direction is absolutely zero.\n", " So uncertainity in velocity along y is zero=> uncertainity in position along y is infinite. \n", "So nothing can be said about its position/motion along \n" ] } ], "prompt_number": 4 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 4.5 Page 116" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#initiation of variable\n", "from math import pi\n", "m=0.145;v=42.5; #'m','v' - mass an velocity of the electron in SI units\n", "h=1.05*10**-34; #planck's constant in SI\n", "p=m*v; #momentum\n", "delp=p*0.01;#due to 1% precision in p\n", "\n", "#calculation\n", "delx = h/delp#uncertainty in position\n", "\n", "#result\n", "print \"Uncertainity in position is %.1e\" %delx;\n", "\n", "#part b\n", "print \"Motion along y is unpredictable as long as the velocity along y is exactly known(as zero).\";" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Uncertainity in position is 1.7e-33\n", "Motion along y is unpredictable as long as the veloity along y is exactly known(as zero).\n" ] } ], "prompt_number": 5 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 4.7 Page 119" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#initiation of variable\n", "from math import sqrt\n", "mc2=2.15*10**-4; #mc2 is the mass of the electron, concidered in Mev for the simplicity in calculations\n", "hc=197.0 # The value of h*c in Mev.fm for simplicity\n", "delx= 10.0 # Given uncertainty in position=diameter of nucleus= 10 fm\n", "\n", "#calculation\n", "delp= hc/delx ; #Uncertainty in momentum per unit 'c' i.e (Mev/c) delp= h/delx =(h*c)/(c*delx);hc=197 Mev.fm 1Mev=1.6*10^-13 Joules')\n", "p=delp; # Equating delp to p as a consequence of equation 4.10\n", "K1=p**2+mc2**2 # The following 3 steps are the steps invlolved in calculating K.E= sqrt((p*c)^2 + (mc^2)^2)- m*c^2\n", "K1=sqrt(K1)\n", "K1= K1-(mc2);\n", "\n", "#result\n", "print \"Kinetic energy was found out to be in Mev is\", round(K1,3)" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Kinetic energy was found out to be in Mev 19.7\n" ] } ], "prompt_number": 14 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 4.8 Page 120" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#initiation of variable\n", "h=6.58*10**-16; # plack's constant\n", "delt1=26.0*10**-9;E1=140.0*10**6 #given values of lifetime and rest energy of charged pi meson\n", "delt2=8.3*10**-17;E2=135.0*10**6; #given values of lifetime and rest energy of uncharged pi meson\n", "delt3=4.4*10**-24;E3=765*10**6; #given values of lifetime and rest energy of rho meson\n", "\n", "#calculation\n", "delE1=h/delt1; k1=delE1/E1; # k is the measure of uncertainity\n", "delE2=h/delt2; k2=delE2/E2;\n", "delE3=h/delt3; k3=delE3/E3;\n", "\n", "#result\n", "print \"Uncertainty in energy of charged pi meson is %.1e\" %k1;\n", "print \"Uncertainty in energy of uncharged pi meson is %.1e\" %k2;\n", "print \"Uncertainty in energy of rho meson is \",round(k3,2);" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Uncertainity in energy of charged pi meson is 1.8e-16\n", "Uncertainity in energy of uncharged pi meson is 5.9e-08\n", "Uncertainity in energy of rho meson is 0.2\n" ] } ], "prompt_number": 9 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 4.9 Page 121" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#initiation of variable\n", "h=1.05*10**-34; #value of planck's constant in J.sec\n", "delx= 1.0; # uncertainty in positon= dimension of the ball\n", "delp=h/delx; # uncertainty in momentum \n", "m=0.1; #mass of the ball in kg\n", "\n", "#calculation\n", "delv=delp/m; # uncertainty in velocity\n", "\n", "#result\n", "print \"The value of minimum velocity was found out to be in m/sec\",delv;" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The value of minimum velocity was found out to be in m/sec 1.05e-33\n" ] } ], "prompt_number": 17 } ], "metadata": {} } ] }