Hi-- I'm doing an end of year project on the physics of trampolines. Anyone who has ever trampolined before knows that you can "double bounce" a person, such that one person bounces right before the other, thus launching the second bouncer higher into the air. In order to do a physics experiment with this, with a high res camera, I videotaped two balls (both 6 lbs), dropped such that one double bounces the other higher into the air, while the other ball barely bounces at all. Can anyone help me explain the physics of this 'phenomena' with equations, and/or as much detail as possible...Thank you. To clarify what I'm talking about specifically watch this video although it is two kids, instead of two balls, the idea is the same. Help would be greatly appreciated. Thanks again.