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Why do balls bounce?

by Mya Kagan (whyzz writer) >> more about the author

Here are some thoughts to bounce around: Have you ever noticed that different kinds of balls seem to bounce differently? If a ball is really full of air, it tends to bounce better than one which is missing some air. You’ve probably also noticed that balls bounce higher from harder surfaces, or that the higher up you are when you drop it, the more it seems to bounce…!  

The reason balls bounce is because of the combination of gravity and energy. Gravity is the force that pulls everything on our planet towards the center of the Earth. In the case of bouncing balls, gravity is what pulls the falling ball towards the ground! As it falls, the ball gains energy from its movement.  

As soon as it hits the ground, all of the energy gained by the ball has to go somewhere! You can think of it basically like the energy is being pushed back inside the ball and then propelling it upwards… or, bouncing!   




Bounce on over!

Find a couple of different balls that are made of different materials. Bounce them all in a few different places, like in the grass and on the sidewalk. Do they bounce differently?

Try bouncing them from higher up and closer to the ground. Do you notice that anything different happens when the ball has time to collect more energy as gravity pulls it towards the ground?





The limerick of Jean-Paul and his ball

There once was a boy named Jean-Paul
His favorite toy was a blue ball
He bounced it so high
Right up to the sky
That one day it went over a wall.

But Jean-Paul knew about The Big Two
That made his ball bounce from his view
Energy, of course
And gravity, the force
Had bounced that ball to somewhere new!