Why Does a Ball Bounce?
When you throw a ball against the floor in order to make it bounce the ball gets out of shape as soon as it comes in contact with the floor. As much of it as strikes the floor becomes perfectly flat, and because the ball has a quality known as elasticity, which means the ability to return to its proper shape, it returns to its shape immediately and in doing so forces itself back into the air and that is the bounce.
Of course, the first thing we think of when we consider something that bounces is a ball, and in most cases a rubber ball. We are more familiar with the bouncing qualities of a rubber ball. Other balls, like standard baseballs, are not so elastic as a rubber ball filled with air, but a solid-rubber ball is more elastic and some golf balls are much more elastic than a solid-rubber ball. The principle is the same, when you drive a golf ball, excepting that when you bounce a ball on the floor the floor does the flattening and when you drive a golf ball, the golf club does the flattening. A baseball flies away from the bat for the same reason. When you meet a fast-pitched ball squarely on the nose with a good swing, it goes farther and faster than when you hit a slow-pitched ball with an equal swing, because in the case of the fast-pitched ball you flatten the ball out more, and it has so much more to do to recover its proper shape that it bounces away from the bat at much greater speed and goes much further unless caught than a slow-pitched ball under the same circumstances.