Hi, what do you want to do?
Bozeman Science
Free Body Diagrams
Mr. Andersen shows you how to draw free body diagrams of various objects. The major forces (like gravity, normal, tension, friction, air resistance, etc.) are discussed and then applied to various problems.
PBS
Pbs Learning Media: Gravity at Earth's Center
In this video segment from NOVA scienceNOW, learn about the effects of gravity as astrophysicist Neil deGrasse Tyson falls through a virtual hole through Earth's center. [1:45]