tag:techtv.mit.edu,:Array/218999940 2009-06-10 14:04:53 -0400 MIT Department of Physics Technical Services Group Two pucks of the same mass are slid at each other on an air table, and their resulting collisions demonstrate conservation of momentum. Notice on the first collision, for example, that when a moving puck hits a stationary puck dead-on, that the second puck leaves with the same velocity as the first, and the first puck stops moving completely. 80