Conservation of Momentum

Purpose:
The purpose of the experiment is to experimentally prove that momentum is conserved in a collision.

Equipment Used:

The picture is of an instrument that records the activity on its level glass surface. The reason the surface is level is because it is designed for small collisions between things like marbles and steel balls. It has to be level since the conservation of momentum in only two directions can be observed by this instrument so if it isn't level then forces such as gravity might be applied to the objects in a manner that will alter their momentum. In this case, one marble is put on a trajectory that will make it collide with another stationary marble in a glancing impact, then both marbles will be in motion and the data should prove that the momentum in both axis are conserved.








Data Collected:
Mass of marble 1 = .0864kg
Mass of marble 2 = .0857kg

The image shows the path of the marbles through the entire experiment. The blue dots are for the marble that is initially in motion and the red dots are for the marble that will be collided with marble that is initially in motion.

The image shows the data of the dots that were taken from the collision. The slopes of the data shows the velocity in both the x-axis and the y-axis for both marbles, before and after the collision. If momentum is conserved then the momentum in the x-axis and y-axis should be conserved.








Calculations:

The momentum in the x-axis before the collision = .0533
The momentum in the y-axis before the collision = 0
The momentum in the x-axis after the collision = .0747
The momentum in the y-axis after the collision = .0054

Conclusion:
Obviously the momentum in either axis isn't conserved, but that isn't proof that momentum isn't conserved. The source of error in this experiment is that the collision between the marbles wasn't a glancing collision, however that alone isn't enough to create a collision where momentum isn't conserved. The table isn't perfectly level, the marbles collided at too high of a velocity and because of the collision the rotation of the marbles might have changed. When all of these factors are combined it can be very easy for it to seem as if momentum isn't conserved.

Sincerely,

Swaggy C