QUESTION #310

What are the physics involved in throwing a frisbee? And why its specific shape?

Asked by: Nancy

Answer

I'm just going to simplify the explanation from Scientific American. You can read the original (better) one at:

http://www.scientificamerican.com/1999/0499issue/0499working.html

Two major factors allow the disc to fly -- aerodynamic lift and angular momentum.

Aerodynamic lift is the same principle that allows airplanes to fly. Like the airplane wing, the frisbee's shape creates a low pressure area above it, and a high pressure pocket below. Since everything moves towards low pressure, the frisbee moves upwards.

The frisbee wouldn't fly, however, if it wasn't spinning. Momentum is conserved, and since the spinning disk has angular momentum, it will resist changes in its orientation; i.e. it won't flip over.
Answered by: Aman Ahuja, Physics student, WPI, Mass.