Investigating the Bounce of a Tennis Ball after It Has Been Dropped From Certain Height

Investigating the Bounce of a Tennis Ball after It Has Been Dropped From Certain Height

Aim

To investigate how high a tennis ball will bounce back after it has

been dropped from a certain height

How a Tennis Ball Bounces

As the ball is elevated the ball gains gravitational potential energy

equal to the ball's weight multiplied by its change in height1. When

the ball is dropped, the height decreases, and therefore so does the

gravitational potential energy. At the same time, the velocity of the

ball increases due to gravity, and therefore the kinetic energy

increases, as kinetic energy half the mass of the object (in this case

the falling ball) multiplied by velocity squared (Source: Physics for

You GCSE textbook). When the ball hits the floor the kinetic energy

goes into deforming the ball from its original round shape to a

squashed, oval shape. A tennis ball contains a rubber shell, which is

filled with compressed gas. The ball is most stable in a round shape,

so the gas inside expands to push the ball back to form the round

shape. This forces the outside of the ball to push out and therefore

bounce back up2. However, the ball will not bounce back to its

original height due to it losing energy as heat and sound energy when

hitting the floor.

Relevant Variables

The independent variable in this investigation is the height that the

ball is dropped from. The dependent variable that will be measured is

the height that the ball bounces back. The control variables that will

need to be kept constant if the results are to be as accurate as

possible are:

1. The weight of the ball; we will use the same ball throughout the

experiment to ensure that the results are as accurate as possible.

2. Material of the ball; as the ball is the same one used, this will

be kept the same also.

3.