Physics Secrets for Hula Hooping

Introduction

Have you ever spent time spinning a hula hoop around your waist or arm? Could you easily do it, or was it difficult? Have you ever wondered how hula hoops work, or, in other words, what makes them be able to spin around a person's waist or arm? It comes down to the physics that is involved. Physics can help you determine what makes one hula hoop a winner and another a flop. In this activity you will get to create your own hula hoops and investigate how their masses affect how they spin. Which do you think will spin better, a heavy hoop or a lighter one? Get ready to do some hula hooping to find out!

Credits

Materials

• Tape measure
• Polypipe, which is hard black tubing usually used for irrigation (5/8, ¾, or 1 inch diameter, about 25 feet in length, although it normally comes in rolls of 100 feet). Available from a garden supply store or home improvement store.
• Poly insert coupling or wooden dowel that fits snugly inside of the polypipe tubing. For example, if you are using ¾-inch tubing, you will want to use a ¾-inch poly insert coupling.
• PVC cutter (preferred, or a utility knife sharp enough and large enough to safely cut through polypipe)
• Hairdryer
• Funnel with an opening that can fit into the polypipe or a thick sheet of paper and tape
• Measuring cup
• Timer or stopwatch
• Wide plastic tape such as duct tape
• Sand (1 C)
• Optional: Bucket and colorful tape or paint for decorating
• Adult helper
• Optional: Another helper to assist in testing the hula hoops