hcho15.html

My sister likes to hang upside down and pretend that things fall up.

Sometimes
this isn't such a
good idea!

Imagine if things actually could fall up. That would be really strange!

I guess for that to happen, we'd have to somehow overcome Earth's gravity.

Gravity is the force that pulls on every object on Earth. I wonder if the pull is always the same for every single thing.

I tried dropping a penny and a pen from the same height at the same time...and they hit the ground at the same time!

Then I tried a pen and a piece of paper. The paper drifted to the floor long after the pen hit.

But then I crumpled it and tried it again.

Can you guess what happened? To find out, put gravity to the test yourself!


	A desk or table
	Ruler
	Different sized marbles
	A notebook and books or a binder

	First make a ramp. You can use a binder notebook, or tilt a small desk or table by putting books under two of the legs. Make sure the ramp is tilted just a little bit, so that the marbles will roll slowly- then you'll be able to watch them better. Also, the smoother the surface the better!
	Take two marbles, a big one and a small one. Line them up evenly at the top of the ramp.
	Use a meter stick or a ruler as a starting gate. If you don't have a meter stick or a ruler, use anything that is straight, like a pencil or a rolled up piece of paper. Hold the starting gate and lift it quickly so that both marbles begin to roll at the same time.

	Watch the finish line closely to see if one marble comes in first or if it's a tie. Keep a sharp eye out to see if there is a winner!
	Do the race at least 3 or 4 times to check for accuracy. It doesn't hurt to try it even more times than that!
*Does one marble win the race, or is it a tie?* *Are the results the same for every race?*

Have you ever noticed the force of a magnet? If you put two magnets next to each other, they will either push or pull on one another. That push or the pull is the force of magnetism. Gravity is a force, too. It arises because all things in the Universe attract each other. The bigger the object, the stronger its force of attraction.

The gravity of Earth has really strong attraction because it's a big planet. (At least until you go comparing our home turf to places like Saturn and Jupiter!) Anyway, the Earth is sure big enough to pull everything toward the ground instead of having it float around.

Hey, I just thought of something, wouldn't it be fun to give gravity a holiday and hover in the air like astronauts? That is, it'd be fun as long as there was something soft to land on when the party was over!!