I remember as a lad jumping on my friends trampoline, we discovered that while two or more people were jumping, one can be launched higher at a particular moment than if jumping solo. How exactly does this “double bounce” occur? Can this be done on or with other objects than a trampoline?
Without really looking into it, i’m assuming some of your friend’s kinetic energy is getting transferred to you. If you’re at the low point in your bounce (and the trampoline material is pushed dow into a sort of funnel shape by your weight), and your friend then lands on the tramp at a higher point, it will tend to push you upwards, thus giving you an extra kick, at the expense of his momentum.
IANA trampolinist but I’d imagine if two jumpers came down on the mat simultaneously and depressed it to it’s full extent and then one person suddenly bent his knees and waist so that the full effect of the rebound energy was spent on the remaining jumper, you’d see a pretty impressive launch sequence.
Yep, that’ll work. I played on a trampoline a lot at summer cam years back, and that’s just how you stop bouncing if your by yourself on it. Bend your knees and squat down partially. Exercise for the smarty-pants’ out there: Where does your kinetic energy go when you do this?
It gets converted by your leg muscles into, what, heat? lactic acid? Actually, isn’t it potential energy stored in the trampoline by absorbing your fall that your body absorbs? If you don’t straighten your legs, it becomes motion; if you bend them, your legs absorb the energy.
We used to do this also on the local pool’s diving board. It has been said how it is done in the above posts. However, with each jumping pass we are brought closer to god. /Rod and Todd
I went through three trampolines as a kid and had my fair share of injuries getting double bounced. I’m pretty sure you guys are wrong about how it is done.
It’s all about the timing of the jumps, neither one of you have to stop jumping. What you do is time your jump so that when you are at your low point your partner is still descending. That way when you start to come back up, he is below the “rest line” of the mat but hasn’t hit it yet because it is still indented. Now when he is on the way down and the mat is on the way up and they meet he’s in for a ride.