Air Hockey Collision

Have you heard of the games air hockey and pool?  Think, what do they have in common.  My physics teacher might say that they both include elastic collisions, meaning two objects hit each other then move apart after contact.  This is different from inelastic collisions like a car accident where two objects hit each other then move connected together.  Inelastic collisions can happen between two hockey pucks on an air hockey table or two balls on a pool table.  In class, we learned that after collision both objects' momentum vectors combined create the same momentum before and after the collision.  We also learned that as the balls/pucks move away they move at a 90 degree angle from one another, that is unless it acts like a pendulum where one stops completely and the other moves straight forward.  To learn more about the physics in pool watch: https://www.youtube.com/watch?v=toFFvsMeUqg.

To test all this out we brought in an air hockey table and took a video of the two pucks colliding and splitting off.  As the pictures above of our experiment show, there was a grid we used to find the distance that the puck moved as well as a timer with the video.  Using these we could find the velocity of the two pucks as well as the direction, both before and after.  Using the momentum equation, P=mv, and the information we gathered including the mass of the pucks, we were able to find the momentum of the pucks before the elastic collision, and both vectors after.  When attaching the vectors together they showed the same initial and final momentums in the system.