We have two sheets of typing paper that came from the same package. They are exactly alike. Does one feel heavier than the other? Does one weigh more (on the scale) than the other?

Of course not. They are the same.

Now crumple one piece, and weigh them both again. Do they still weigh the same as each other?

Certainly.

Stand on a chair and drop both sheets of paper at the same time. Do they both hit the floor at the same time?

Why not? They are the same size, and of the same weight.

Which one hit the floor first? The crumpled one, wasn't it? The crumpled paper just fell to the floor--zoom. The flat paper sort of floated to the floor, slowly and gracefully. Why?

Probably the flat piece has more surface area and must push more air aside as it falls.

You may think about this, and extend it a bit, the next time you see somebody jump from a plane and float to earth on a parachute!

Since air offers resistance to objects moving through it, you can have fun playing with a whirlybird or pinwheel. Cut the whirlybird from paper or cardboard, and fold as ' your teacher can show you.

By tossing the heavy end of the whirlybird into the air, you can see that air affects the whirlybird's fall.

Put a pinwheel onto a stick and wave the pinwheel in the air. Now, put a flat paper onto a stick, and see what happens when you wave it.

Now just wave the empty stick--there isn't much for the air to resist, and it is much easier to wave. But, it isn't any fun at all!