What Makes a Frisbee Fly?
If you have ever been to the park or the beach, you've probably seen one of these plastic discs flying through the air. We're not talking about a UFO, we're talking about the Frisbee, more commonly known as the flying disc. What makes a Frisbee fly? Just like a bird's wing or the wing of an airplane, shape plays a large part in influencing the flying ability of the Frisbee.
If we take a look at the Frisbee from the side, we can see that the rounded edges of the Frisbee look similar to the front edge of an aircraft wing. We know that the curved upper surface of the wing is what generates (causes) lift. The same principle applies to the Frisbee. As air passes over the curved upper surface of the Frisbee it speeds up, creating a low pressure region on top of the Frisbee. Below the Frisbee, air passes more slowly, creating a high pressure region. The difference in pressure gives the Frisbee lift. The shape of the Frisbee generates lift, but it needs more than that for flight.
Try throwing a Frisbee without spinning it. Notice how it wobbles and tumbles. The shape of the Frisbee may be generating lift, but the Frisbee is unstable. It cannot stay upright and eventually stalls (falls). All flying things must have something that makes them stable during flight; airplanes and birds have tails, rockets have fins. For a Frisbee, it is the spinning motion generated from the Frisbee throw that stabilizes the Frisbee as it flies.
