How High Will a Ball Bounce?
Showing your students a regular ball such as a super bounce ball or a ping pong ball, survey the class to determine the height to which they predict the ball will bounce if dropped straight down without adding any energy. You may be surprised to learn that some students will predict that the ball with bounce higher than the point from which you drop it. Drop the ball. Students will discover that the ball will never reach the height from which you dropped it. The Law of Conservation of Energy states that energy cannot be created or destroyed; it can only be transferred as alternate forms of energy. The energy that initially went into the system was transferred out as sound energy and heat energy. The ball will never bounce higher than the initial drop point because the energy that comes out of a system can never exceed the energy that goes in. Explain to your students that the ball’s energy was stored due to it position above the ground. Because of the force due to gravity, the ball fal
