A hula hoop stays up due to the balancing force of friction between a person's body and the hoop, which exactly counters the downward force of gravity pulling on the hoop. When a person moves their body while hula hooping, they use the normal force to keep the hoop spinning, but if they stop moving or the hoop loses contact, gravity overcomes the normal force and pulls the hoop down.

1. How does a Hula Hoop work?

2. What is the force that keeps a hula hoop up? The force trying to make the hoop fall is…..? Gravity

3. So, what force keeps the hoop going? Friction The force of friction between your body and the hoop exactly equals the pull of gravity, so the hoop doesn't fall.

4. This frictional force is opposite to the direction of motion (down) and must exactly equal the force of gravity to keep the hoop going.

5. When you move your body, you are using Normal Force to keep the hoop going. When you stop moving, or if the hoop loses contact with you body, the Normal Force drops and Gravity pulls the hoop down.

6. Let’s go and do some hula hooping!