Matth

Abstract

Many sports use a ball in some way or another. We throw them, dribble them, hit them, kick them, and they always bounce back! What makes a ball so bouncy? In this experiment you can investigate the effect of air pressure on ball bouncing.

Introduction

Bouncing is what makes playing with a ball so much fun. But what makes a ball bounce? If you were to see a ball drop to the forum' in slow motion, you would see its shape change dramatically. When it hits the ground, the bottom of the ball becomes flat against the floor. Then when it bounces up, it returns to its original shape. The changes in shape are due to a balance of forces and energy:

"When you drop a ball, gravity pulls it toward the floor. The ball gains energy of motion, known as kinetic energy. When the ball hits the floor and stops, that energy has to go somewhere. The energy goes into deforming the ball-- from its original round shape to a squashed shape. When the ball deforms, its molecules are stretched apart i