You are playing pool. All the balls are the same mass. You hit the 8 ball with your cue and it moves away at 1.3 cm/second going due East. It hits the 13 ball and the 13 ball moves off to the East at 0.9 cm/sec. What does the 8 ball do?
it would transfer most of it's kinetic energy to the 13 ball and then either stop moving or move backwards slowly until it stops moving...
but what does this have to do with astronomy?
