This page, created by Tom Henderson of Glenbrook South High School, features an animated image and a discussion of the forces involved in going through a looping coaster. This page is fairly simplistic, but it does provides links to other helpful physics resources. Some of these include lesson plans discussing the subjects of: acceleration, net force and acceleration, free body diagrams, weightlessness, circular motion and tangential velocity, circular motion and acceleration, the centripetal force requirement and amusement park physics. All together, this is a nice resource for an upper high school to lower undergraduate level course in basic physics.