# Chapter 6 :Momentum¶

## Example 6.3 , Page no:37¶

In [1]:
import math
from __future__ import division

#initialisation of variables
m=50; #mass in kg
v=6; #velocity in m/sec

#CALCULATIONS
p=m*v; #calculating momentum

#RESULTS
print"Momentum of woman in kg.m/sec =",round(p,3);

Momentum of woman in kg.m/sec = 300.0


## Example 6.4 , Page no:37¶

In [2]:
import math
from __future__ import division

#initialisation of variables
w=160; #weight in lb
g=32; #g in ft/sec square

#CALCULATIONS
m=w/g; #calculating m in slugs
v=(1*5280)/(4*60); #calculating v in ft/sec
mom=m*v; #calculating avg. momentum in slug.ft/sec

#RESULTS
print"Average Momentum in slug.ft/sec =",round(mom,3);

Average Momentum in slug.ft/sec = 110.0


## Example 6.6 , Page no:37¶

In [3]:
import math
from __future__ import division

#initialisation of variables
mr=5; #weight of rifle in kg
mb=0.015; #weight of bullet in kg
vb=600; #velocity of bullet in m/sec

#CALCULATIONS
vr=(mb*vb)/mr; #calculating vr using law of conservation of momentum

#RESULTS
print"Recoil velocity of rifle in m/sec =",round(vr,3);

Recoil velocity of rifle in m/sec = 1.8


## Example 6.7 , Page no:37¶

In [4]:
import math
from __future__ import division

#initialisation of variables
wa=300; #weight of astronaut in lb
ww=1; #weight in of wrench lb
vw=15; #velocity of wrench in ft/sec

#CALCULATIONS
va=(ww*vw)/wa; #calculating va using law of conservation of momentum

#RESULTS
print"Velocity of astronaut in ft/sec =",round(va,3);

Velocity of astronaut in ft/sec = 0.05


## Example 6.8 , Page no:38¶

In [5]:
import math
from __future__ import division

#initialisation of variables
mm=70; #weight in of man kg
ms=0.5; #weight of snow-ball in kg
v1=20; #man's initial velocity in m/sec

#CALCULATIONS
v2=(ms/(mm+ms))*v1; #calculating v2 using law of conservation of momentum

#RESULTS
print"Mans final velocity in m/sec =",round(v2,3);

Mans final velocity in m/sec = 0.142


## Example 6.9 , Page no:38¶

In [6]:
import math
from __future__ import division

#initialisation of variables
m1=40; #weight in kg
m2=60; #weight in kg
v1=4; #speed in m/sec
v2=2; #speed in m/sec

#CALCULATIONS
v3=((m1*v1)+(m2*v2))/(m1+m2); #calculating v3 using law of conservation of momentum
inKE=(1/2)*(m1*v1*v1)+(1/2)*(m2*v2*v2); #calculating initial KE in Joules
fiKE=(1/2)*(m1+m2)*v3*v3; #calculating final KE in Joules
fiKe1=inKE-fiKE;

#RESULTS
print"Final velocity in m/sec =",round(v3,3);
print"Kinetic Energy lost in Joules =",round(fiKe1,3);

Final velocity in m/sec = 2.8
Kinetic Energy lost in Joules = 48.0


## Example 6.10 , Page no:38¶

In [7]:
import math
from __future__ import division

#initialisation of variables
m1=40; #weight in kg
m2=60; #weight in kg
v1=4; #velocity in m/sec
v2=-2; #velocity in m/sec

#CALCULATIONS
v3=((m1*v1)+(m2*v2))/(m1+m2); #calculating v3 using law of conservation of momentum
fiKE=(1/2)*(m1+m2)*v3*v3; #calculating initial KE in Joules
inKE=(1/2)*((m1*v1*v1)+(m2*v2*v2)); #calculating final KE in Joules
inKE1=inKE-fiKE;

#RESULTS
print"Final velocity in m/sec =",round(v3,3);
print"Kinetic Energy lost in Joules =",round(inKE1,3);

Final velocity in m/sec = 0.4
Kinetic Energy lost in Joules = 432.0