Re: Why does a hula hoop stay up and why does a heavier one stay up longer?

You're right! A heavier hula hoop will stay up better than a light one. That's a very good observation. In physics, we would say that the heavier hula hoop has more inertia.

Inertia is kind of a fancy word, but the idea is really pretty easy. All that it means is that things want to keep doing what they're already doing. If something is not moving, then it wants to stay still. If it's already moving, then it wants to keep going. Heavier things have more inertia than light ones. So they really want to keep doing what they're doing.

Think of a car versus a bicycle. If a car is sitting still, it would be very hard to push it and make it move. But it isn't very difficult to push a bike to make it move. That's because the car is heavier and has more inertia. Same thing if they're already moving. If a car was rolling away, it would be very hard to make it stop. But it would not be as difficult to stop the moving bicycle.

This same effect is true for hula hoops. The heavier hula hoop has more inertia. So it wants to keep going in a circle around you. But the light hula hoop has less inertia, so it's very easy to stop it and then it falls down.

I hope that helps! Have fun hula hooping!

Your Mad Scientist,
Mike Scannell