NINJA BALLS : DEMONSTRATE EFFECT OF ELASTIC COLLISIONS OF OBJECTS OF DIFFERING SIZES
(DRAMATIC DEMONSTRATION OF MOMENTUM CONSERVATION)
Drop this little doofus, big-ball down, and the 4 ball collision that results when the big one hit the floor sends the little one off upwards at a very high velocity. (Drop it off to one side, do not look down at it).
Theory for two-ball collision, showing how vastly different end speeds can come out when two balls with mass ratio G collide going at the same initial speed. The Ninja Ball device cascades this effect with great effect.