The Bouncing Ball Energy Test — Reading Comprehension

Have you ever wondered why a basketball doesn't bounce forever? Or why a tennis ball gets warmer after you hit it a bunch of times? 

The answer is all about energy transfer! Energy is the ability to do work or cause change. When you drop a ball, it has a type of energy called potential energy, which is stored energy due to its position high off the ground. The higher the ball, the more potential energy it has.

As the ball falls, its potential energy changes into another type of energy called kinetic energy. Kinetic energy is the energy of motion. Just before the ball hits the floor, it is moving at its fastest speed and has its most kinetic energy.

When the ball hits the floor, something amazing happens. The kinetic energy doesn't just disappear; it gets transferred and converted into other forms of energy. 

This is a scientific rule called the Law of Conservation of Energy, which states that energy cannot be created or destroyed, only transferred or changed from one form to another.

What forms of energy does the kinetic energy become? A lot of it turns into sound energy! You hear a "thump" or a "thwack" when the ball hits the ground. That sound is a form of energy. Another part of the kinetic energy is converted into heat energy. The tiny particles in the ball and the floor vibrate faster when they collide, which is how heat is produced. This is why the ball might feel a little warmer after a lot of bouncing. The conversion of energy also causes the ball to slightly deform, or change shape, which also uses up some energy.

Because some of the ball's kinetic energy is converted into sound and heat, there isn't as much energy left to make the ball bounce back up to its original height. Each time the ball hits the ground, it loses a little more energy to sound, heat, and other things. This is why the ball's bounces get lower and lower until it finally stops.

Fun Fact: If you were to bounce a ball on a solid steel plate and a soft foam mat from the same height, it would bounce higher on the steel plate. This is because the steel is a much harder surface, so less of the ball's energy is converted into heat and sound, leaving more for the bounce!

What happens to a ball's kinetic energy when it hits the floor?

Why does a bouncing ball not reach its original height?

A ball is dropped from a high shelf. When does it have the most kinetic energy?

If you drop a ball on a soft rug, how would its bounce be different than on a hard floor?

Imagine a heavy ball and a light ball are dropped from the same height. Which one has more kinetic energy just before hitting the floor?

A student drops a ball from a tall ladder. She wants to see if the ball will bounce higher if she pushes it down. Based on the passage, what would you predict?

What is energy?

When a ball is dropped, its potential energy