Defining Pi for Physics (4:16)
Pi is defined as the ratio of the circumference of a circle to its diameter. A frisbee is used to show the definition of pi. The units for pi, radians, are discussed. The conversion factor between revolutions, degrees, and radians is introduced.
This is an AP Physics 1 topic.

Content Times:
0:22 The definition of pi
0:49 Demonstrating the definition of pi
1:35 The units for pi (radians)
2:04 revolutions, degrees, and radians
2:28 Please use rad for radians (not r, that is for radius)