Magnet Passing Through Copper Pipe


When a strong rare earth magnet moves through a copper pipe, the changing magnetic field induces large circular currents in the copper pipe. Those currents act on the magnet with a force that is opposte to the movement of the magnet. In effect, the physical "work" of gravity is dissipated as heat in the pipe that is being heated slightly by the current, and, thus, the magnet falls a lot slower than it would in free fall.

See the video here.

(Click on the thumbnail images to enlarge)