This classic device is used to demonstrate the conservation of mechanical energy and its conversion from one form to another.� After the wheel is rotated by hand to roll the supporting cords to the top and then released, its potential energy turns into kinetic energy of rotation as it falls.� After the wheel reaches its bottom position, the kinetic energy changes back to potential energy as it rolls the cords up again.� This process continues until all the energy is lost to friction.� All metal construction.� Includes activity guide.�