Trampoline

A trampoline is a device consisting of a piece of taut, strong fabric stretched between a steel frame using many coiled springs. Not all trampolines have springs, as the Springfree Trampoline uses glass-reinforced plastic rods. People bounce on trampolines for recreational and competitive purposes.
The fabric that users bounce on (commonly known as the "bounce mat" or "trampoline bed") is not elastic itself; the elasticity is provided by the springs that connect it to the frame, which store potential energy.

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