IntroductionAre you good at tossing a Frisbee? Have you ever wondered how a Frisbee is able to fly through the air so well? If you can throw a perfect, arcing curve right on target, you've already trained your arm to aid in the aerodynamics of Frisbee flight! In this activity, you'll investigate how the angle at which you throw the Frisbee affects its flight direction and distance. Next time you're out tossing a Frisbee, this little lesson in aerodynamics may help make your throws even more accurate!
This activity is not appropriate for use as a science fair project. Good science fair projects have a stronger focus on controlling variables, taking accurate measurements, and analyzing data. To find a science fair project that is just right for you, browse our library of over 1,200 Science Fair Project Ideas or use the Topic Selection Wizard to get a personalized project recommendation.
BackgroundTwo key forces that act on a Frisbee during flight are lift and drag. Lift is the force that allows the Frisbee to stay airborne, and in flight it opposes the force of gravity on the disk's mass. The Frisbee itself creates this lift force as it flies through the air. Because of the Frisbee's curved shape, the airflow above it must travel at a higher velocity than that underneath, thereby creating low pressure above and high pressure below the disk. This pressure difference provides the lift. Drag is a resistant force on the Frisbee, perpendicular to the lift, and it acts against the disk's movement through the air. The angle at which the Frisbee is thrown, which we'll call the "launch angle" (aka the angle of attack), affects both lift and drag.
As a side note, you've probably noticed that a Frisbee doesn't travel far if it's thrown without spin. Spinning the Frisbee helps it fly by supplying angular momentum, which helps keep the Frisbee stable; the faster it spins, the more stable it should be.
Extra: In this activity, you investigated how the Frisbee's launch angle affects its flight distance and direction, but you only tested a few angles. You can try this activity again but test even more angles, such as angles in between the ones you tried in this activity. You can videotape your throws and then watch the video to analyze and confirm the angles at which you threw the Frisbee. How well does the Frisbee fly using other launch angles? Is there an angle that consistently correlates with the "best" flight in terms of distance and stability?
Extra: In this activity there was not a focus on the effects of wind on a Frisbee's trajectory, but it can definitely be a factor. How will the Frisbee's flight be affected by throwing it into the wind? What about across or with the wind? How does the launch angle change a flight in each of these conditions?
Extra: You could compare the flight of a Frisbee with that of an aerobie (flying ring disk). What differences do you notice? Can you explain them in terms of aerodynamic forces?
Observations and ResultsWhen you threw the Frisbee as flat and horizontal as you could, did it generally fly relatively straight (not far to the left or right) and pretty far? When you threw the Frisbee tilted up a little, did it fly pretty high and far but not as straight, going off to the side near the end of its flight? When you threw the Frisbee tilted down a little, did it fly not nearly as far—and did it also go off to the side?
To fly well, the Frisbee needs enough lift, and not too much drag. When the Frisbee is thrown tilted downward, it does not have much lift and so it quickly falls to the ground. When the Frisbee is thrown relatively horizontal, it has a good amount of lift and consequently should fly relatively far—at least much farther than when the Frisbee was thrown tilted down. When an even larger launch angle is used, the Frisbee has more lift. You may have noticed, however, that although the Frisbee thrown upward flew relatively high, it probably stalled out rather abruptly near the end of its flight. This may have caused it to land gently and/or quickly go off to the side. Of the three launch angles tested in this activity, the horizontal launches probably resulted in the overall "best" Frisbee throws in terms of distance and straightness.
More to Explore
What Do a Submarine, a Rocket, and a Football Have in Common? from Scientific American
Teisha Rowland, PhD, Science Buddies
Science Buddies |
Aerodynamics, forces, physics, lift, drag
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