# Chapter 48 WAVES AND PROPOGATION¶

## Example 48.1 Velocity and Wavelength of particle¶

In [1]:
from __future__ import division
import math
k=100*(1.6*(10**-19))
m=9.1*(10**-31)

v=math.sqrt(((2*k)/(m)))
print("Velocity in m/s %.1f"%v)
h=6.6*(10**-34)
p=5.4*(10**-34)
lamda=h/p
print("Wavelength in A %.3f"%lamda)

Velocity in m/s 5929994.5
Wavelength in A 1.222


## Example 48.2 Quantized energy¶

In [2]:
from __future__ import division
n=1
h=(6.6)*10**-34 #j/sec
m=9.1*(10**-31)  #in kg
l=1*(10**-9)  #in m
E=(n**2)*((h**2)/(8*m*(l**2)))
print("Energy in Joule= %.3e"%E)

Energy in Joule= 5.984e-20


## Example 48.3 Quantum number¶

In [3]:
from __future__ import division
import math
m=10**-9    #in kg
v=10**-6    #in m/s
l=10**-4    #in m
h=(6.6)*(10**-34)  #j/s
E=(0.5)*m*(v**2)
print("Energy in joule= %.3e"%E)
n=(l/h)*(math.sqrt(8*m*E))
print("Quantum number= %.3e"%n)

Energy in joule= 5.000e-22
Quantum number= 3.030e+14


## Example 48.5 Position of electron¶

In [4]:
from __future__ import division
m=9.1*(10**-31)  #in kg
v=300 #in m/s
h=6.6*(10**-34) #in j-s
p=m*v
print("The electrom momentum in kg-m/s= %.3e"%p)
delta_p=(0.0001)*p
print("Delta_p in kg-m/s= %.3e"%delta_p)
delta_x=(h/delta_p)
print("Minimum uncertainaity in m= %.5f"%delta_x)

The electrom momentum in kg-m/s= 2.730e-28
Delta_p in kg-m/s= 2.730e-32
Minimum uncertainaity in m= 0.02418


## Example 48.6 Position of electron¶

In [5]:
from __future__ import division
m=0.05 #in kg
v=300  #m/s
delta_p=m*v
print("Momentum in kg-m/s=",delta_p)
delta_x=(6.6*10**-34)/delta_p
print("Delta_x in meter= %.3e"%delta_x)

Momentum in kg-m/s= 15.0
Delta_x in meter= 4.400e-35