A trampoline is made out of a metal frame attached to legs that hold it above the floor. Inside the frame is a durable piece of fabric such as nylon, polypropylene or canvas, which the user stands on. The fabric is attached to the frame by metal springs or sometimes elastic cords. By jumping repeatedly on the fabric, the user can get as high as 20 feet above the surface of the trampoline.
Storing Energy
When you jump on a trampoline, you push down on the fabric, which pulls on the springs or elastic cords. This causes the cords to stretch out, storing energy. A moment later, the cords snap back, pushing up on your feet again and helping to send you up into the air.
Higher and Higher
If you time your second jump right, you can get higher than the first time. That is because you have some energy stored in the springs from your previous jump, plus the energy from your current jump to propel you up into the air. Since you are jumping higher the second time, you will fall farther and land with more force, storing even more energy in the trampoline. Over several jumps, a skilled trampolinist can get high enough into the air to do flips, spins and other fantastic tricks.
