The height to which a ball bounces depends on several factors:
1) The height from which it is dropped,
2) Whether it was thrown down or just dropped and how hard it was thrown,
3) How much energy is lost in the ball during the collision with the floor
4) How much energy is lost in the floor during the collision with the ball.
5) Some slowing from air resistance (but not so small if the ball is a balloon or made from styrofoam for instance).
Assuming that the experiments are properly "controlled", that is, everything but the ball type is the same, then what is different is how much energy is lost in the ball. Ping-pong balls are very stiff and springy -- they lose only a small fraction of their energy when they bounce on a hard surface. On a soft, squishy surface, the ping-pong ball may bounce less well (but then again, the other balls may bounce less well also). Some surfaces are very complicated, like a mattress. If you drop a ping-pong ball from a meter’s height on a mattress, it will probably lose almost all of its energy in the cloth and padding and not bounce much at all. If you drop a basketball or a heavy steel sphere, then the mattress springs become more important and some energy will be returned to the ball and it will probably bounce higher than the ping-pong ball. But against a hard surface, ping-pong balls do very well (and if the surface is very hard and solid, the steel sphere might do even better, if it doesn’t chip or break the surface first, as it might if the surface is made of concrete or tile).
(republished on 07/11/06)