Question: Can an egg really bounce?

Materials:

• 1 basketball
• 1 tennis ball
• 1 metre ruler
• 1 plastic zip-lock bag or sandwich bag
• 1 raw egg
• Flat or level ground
• Protective goggles (sunglasses would also work) - optional
• Adult helper

Note: Be sure to wear old clothes too!

Procedure:

1. Hold the basketball and tennis ball at the same height. Predict which one of these balls will hit the ground first.
2. Drop a plastic bag to the ground. Does it fall at the same rate as a tennis ball?
3. Stand up a metre ruler and place a basketball on top of it. Predict, or guess, how far up the ruler you think the ball will bounce if dropped. Then, drop the basketball and measure how high it did bounce.
4. Try the same thing with the tennis ball.
5. Put the raw egg on top of the ruler and predict how high it will bounce (just kidding!! If you do this, you'll have a real mess.)
6. Hold the basketball with a tennis ball on top of it at waist height. Predict what will happen if you drop the two balls together. Then drop them and see what happens.
7. Place the egg on top of the basketball at waist height. Predict what will happen if you drop the two together. Then drop them and see what happens.

What Happened - and Why?

The basketball and tennis ball, by themselves, both hit the ground at about the same time because gravity makes heavy and light objects fall at the same rate. (Most people think it matters how much things weigh, but that's not true!)

When the plastic bag was dropped, it took much more time to reach the ground. That's because air gets in the way, making it fall slowly. Actually, anything that is thin, fluffy or flat will act a bit like a parachute and fall more slowly.