Provides a most impressive demonstration of potential energy being transformed into kinetic energy and vice versa. The aluminum track is more than 12 feet long. As the colored 1-3/4 inch plastic sphere rolls down the track and circles around the loop, even the students farthest back in the classroom will have an unobstructed view of a fundamental physical law in action. By releasing the sphere at lower positions along the track, it will go partly around the loop but leave the track at the top. Sphere of plastic and chrome steel are provided to show that the transformation of energy and the velocity of descent do not depend on mass.