Why Does a Ball Bounce?
No matter if a ball is solid or inflated, it bounces because it is elastic. Take a rubber ball and squeeze it in your hand. When you let it go, it snaps back to its round shape.
When you throw a ball against the floor, it becomes a little flattened or is temporarily deformed. As it springs back to its round shape, it pushes away from the floor — it bounces!
According to the Newton’s third law, to every action there is equal and opposite reaction. Because of elasticity, the ball tends to regain its original shape for which it presses the ground and bounces up (due to the Newton’s Third Law of motion).
The elasticity of a ball is important for the sport in which the ball is used. A tennis ball, for example, must have a great deal of bounce. A football bounces less, and a baseball has less bounce than either of the others.