# See the Keys to Success – Chapter 3, pages 4 and 5 for an explanation and pictures.When a ball is dr

See the Keys to Success – Chapter 3, pages 4 and 5 for an explanation and pictures.When a ball is dropped from a height above a floor (consider the floor to be the datum level), originally the ball has all potential energy. As soon as it is dropped, the potential energy starts to change into kinetic energy. (The potential energy decreases and the kinetic energy increases.)When it reaches the floor, all the potential energy has been converted into Kinetic energy and the potential energy is zero. During the collision with the floor, the kinetic energy is converted into elastic potential energy. The speed of the ball becomes zero and then the elastic potential energy is converted back into kinetic energy (note the velocity of the ball is now up, not down. How high up the ball will bounce depends on the type of collision. In a real life situation, some energy will be lost during the collision, so the ball does not return to its original starting position.