Chapter 47 LIGHT AND QUANTUM PHYSICS

Example 47.1 Velocity

from __future__ import division
import math
k=20 #in nt/m
m=1  #in kg

v=(math.sqrt((k)/(m)))*(1/(2*math.pi))
print("Velocity in cycles/s %.5f"%v)

Velocity in cycles/s 0.71176

Example 47.2 Time calculation

P=(10**(-3))*(3*10**(-18))/(300)
print("Power in j-sec %e"%P)
s=1.6*(10**(-19))
t=(5*s)/P
print("Time reqired in sec =",t)
one_sec=0.000277778 #hr
in_hour=one_sec*t
print("Time required in hour %.5f"%in_hour)

Power in j-sec 1.000000e-23
('Time reqired in sec =', 80000.0)
Time required in hour 22.22224

Example 47.3 Work function for sodium

h=6.63*10**(-34) #in joule/sec
v=4.39*10**(14) #cycles/sec
E_o=h*(v)
print("Energy in joule= %.3e"%E_o)

Energy in joule= 2.911e-19

Example 47.4 Kinetic energy to be imparten on recoiling electron

from __future__ import division
import math
h=(6.63)*10**-34
m=9.11*10**-31
c=3*10**8
delta_h=(h/(m*c))*(1-math.cos(90))
print("(A) Compton shift in meter %.3e",delta_h)
delta=1*10**-10
k=(h*c*delta_h)/(delta*(delta+delta_h))
print("(B) Kinetic energy in joules",k)

('(A) Compton shift in meter %.3e', 3.512889892036735e-12)
('(B) Kinetic energy in joules', 6.750017319146053e-17)