Centripetal force and gravitation

Why do things move in circles? Seriously. Why does *anything* ever move in a circle (straight lines seem much more natural)? Is something moving in a circle at a constant speed accelerating? If so, in what direction? This tutorial will help you get your mind around this super-fun topic.

Learn how to deal with centripetal forces and how to relate it to speed, tension, normal force, and radius.

Why are you sticking to your chair (ignoring the spilled glue)? Why does the earth orbit the sun (or does it)? How high could I throw my dog on the moon? Gravitation defines our everyday life and the structure of the universe. This tutorial will introduce it to you in the Newtonian sense.