Coin and Paper Race: The Science of Air & Gravity

What can you learn about gravity and air from a coin and a piece of paper? Quite a bit, actually.

Our coin and paper race was fun and educational. 

What You Need to Do It
A large coin (we used a half dollar)
Heavyweight cardstock
Scissors

What to Do: PART 1
Cut the cardstock so you have a circle just a tiny bit smaller than the coin.

Hold the paper circle in one hand and the coin in another. Drop them at the same time. Which hit the ground first?

The coin did. Why?

The paper is lightweight so despite the fact that it's surface is the same size as the coin, it is easily disturbed by the air, therefore it flits and flutters on its way down to the ground. The coin, however, is heavy so nothing disturbs the gravitational pull.

What to Do: PART 2
Now place the paper circle directly on top of the coin. Hold the edges of the coin without touching the paper, and drop them from one hand.

What happens? The paper and coin travel as one.

Why? 

The coin as it falls, pulls air immediately behind, and the paper stays in place on top of the coin because it's caught in the pocket of air.

This is our second experiment from E. Richard Churchill's book 365 Simple Science Experiments book. It won't be our last!