When the ball hits the ground, all that kinetic energy has to go somewhere. A lot of it goes back into the ball, giving it more force to pop back up into the air—so the higher the potential energy, the higher the kinetic energy, and the higher the kinetic energy, the higher the bounce!

Why are polymers bouncy?

Store-bought bouncy balls are made of rubber, another material that is made up of polymers. When the bouncy ball is stretched, these polymer chains uncoil and straighten. When released, the chains coil back up again. This makes the material stretchy and bouncy.

What factors affect how high balls bounce?

The combination of the material properties of a ball (surface textures, actual materials, amount of air, hardness/ softness, and so on) affects the height of its bounce.