Experiment 7 – Conservation of Momentum
Aim: To investigate the conservation of momentum in elastic
& inelastic collisions and in an explosion.
Apparatus – Air track, trolleys, digital counter, mass balance
Sources of error and precautions 1.
2.
Method A – Elastic Collision
The air track was set up and adjusted on a horizontal surface. The
first light gate was fixed at 42 cm and attached to the digital counter
socket marked stop A. The second light gate distance was set up at
100 cm and attached to socket Start B while the third light gate was
set up at 130 cm and connected to socket stop B.
The electromagnet was set up and attached to socket start A. An
elastic band was set up next to the electromagnet to act as the
pushing force. Trolley A and B were weighed on a mass balance. The
counter was switched on; the trolleys were placed on the air track
one touching the electromagnet and one at the 98 cm mark so that
the distance covered by each trolley is 30 cm. The start button on
the counter was pressed. After time A is recorded Timer B is resetted so that it could read the exact time taken to cover distance B
only. The time recorded by the counter was written down in the
results.
This procedure was repeated using different masses on the trolley.
The velocity and momentum of the two trolleys before and after
collision was calculated.
Results:
Trolley
Mass
of
trolley
Kg
Distance
covered
m
Time
s
Velocity
v=2s
t
m/s
Momentum
Mom = M * V
Kg m/s
1 st Try
Momentum before collision
A
B
A
B
***
Momentum after collision
***
2 nd Try
Momentum before collision
A
B
A
B
***
Momentum after collision
***
Conclusion:
1. From the experiment it was observed that the energy of trolley A
was ___________ to trolley B.
2. From the result table it can be seen that the momentum of trolley
A is ____________to that of trolley ________. Also the sum of the
momentum ________ collision of A is equal to the sum of the
momentum _________collision.
3. So we can clearly state that momentum is
______________________
4. Momentum __________________is equal to momentum
________________________.