Bungee jumping is an activity that involves jumping from a tall structure while connected to a large elastic cord. The tall structure is usually a fixed object, such as a building, bridge or crane; but it is also possible to jump from a movable object, such as a hot-air-balloon or helicopter, that has the ability to hover over one spot on the ground. The thrill comes as much from the free-falling as from the rebounds.
When the person jumps, the cord stretches to transform the gravitational potential energy and kinetic energy of the fall, then the jumper flies upwards again as the cord snaps back. The jumper oscillates up and down until all the energy is transformed into heat, sound, and other forms of non-mechanical energy.