22-Apr-2015 2D Collision

Purpose

The purpose of this lab is to observe a 2-D collision and to see if the momentum and energy of the balls colliding is conserved or not. In this experiment we are doing two collisions one with with a marble and a steel ball and the other with two steel balls.

Experiment

The setup for this experiment was a glass table where the ball could roll on with little to no friction and a camera above it to record the collisions. The video two collisions are then taken and analysed in logger pro. The collision is done by have one ball originally stationary and the the other is rolled towards the stationary one so that it causes a collision. 

 

The analysis of videos of the collisions were done by manually placing points along the path that the ball was traveling.  From the data gathered from the videos we are able to find the x and y velocities of the balls during the collision. Below we took the numbers we got from our data to calculate to momentum of each collision, the first set is for the steel and marble collision the second set it for the steel on steel collision. From the calculations that we made it can be seen that momentum is conserved in our collision.

After we compared the momentum for both collisions we then look at the energy for each collision to see if the energy was conserved during both collisions or not. From both of the graph the first one for steel with marble, and the second one with steel with steel, We see that energy is conserved because the potential energy in the x and y direction are in sync while the kinetic energy is almost a perfect mirror opposite.

From our momentum calculations it can be seen that there are some errors between the initial and final values. One of the reasons that cause this error would be the fact the lens for the camera is curved and that as the ball passes through the middle of the lens it would appear to move faster. Another would be that the surface is not completely frictionless on the table or the ball. Lastly the table was slightly slanted even though we tried to use note cards to level the table it may have still be slightly off.