When a cart is sent down the track, it appears to change color while passing through the tunnel. The force of gravity is balanced by the tension in two strings, illustrating vector addition of forces. A heavy bob on a long string. A ballistic pendulum is used to measure kinetic energy. A computer simulation of the Hunter-Monkey problem.
Air is feeble fuel compared to water.
G A ball is projected from the lecture bench onto the floor. A qualitative demonstration of a Cavendish balance. By rotating the plane of oscillation of a rigid pendulum, the component of gravity accelerating the pendulum is varied. An object rolls back and forth between the ends of a shallow trough in apparent perpetual motion. If the object is started from below the end of the trough, it will climb higher in apparent violation of energy conservation.