Precession

This demonstration uses a gyroscope (a bicycle wheel works well), string, and a turntable (optional) to show how the equatorial bulge of Earth causes precession. By balancing the spinning bicycle wheel on one hand, and pulling a string attached to the top axle with the other, the axis of the wheel traces out a circle (precesses). The site also explains how the moment of inertia is related to torque and precession. Educational levels: High school, Middle school, Undergraduate lower division