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Weekend Spotlight: The Wonders of Gravity

Exploring Gravity at Home

Aristotle believed that the heavier something is, the faster it will fall to Earth.  Do you believe this? Prove it!

What you need:

1. A small package of modeling clay divided into three equal sections, rolled into balls.
2. A cookie baking pan (preferred) or a hard floor.

What to do:

1. Drop two of the small clay balls at the same time onto the cookie pan and see if they fall at the same speed. It would be best to have one person drop the clay balls and one person watch them.
2. Combine those two balls to make one larger ball.  This one should be twice the weight.
3. Now drop the large ball and the remaining small ball at the same time. Do they reach the ground at the same time? If not, which one reaches the ground first?

Don't read any further if you want to try to experiment before finding the answer!

Answer:

Aristotle was wrong. Galileo showed that all things fall at the same rate, no matter how much they weigh. The two balls, although different in weight, fall at the same speed.

Why doesn't a feather or a piece of paper fall at the same speed as the clay ball? They would if it wasn't for air resistance.  The feather catches a lot of air during its fall, which slows it down. You can demonstrate this by dropping a flat piece of paper and a crinkled up piece of paper at the same time. The flat paper will fall slower because it catches more air resistance than the crinkled up one does.