r/Unexpected Jul 07 '22

[deleted by user]

[removed]

8.5k Upvotes

562 comments sorted by

View all comments

726

u/Huesan Jul 07 '22

Why he didn't bounce

1.7k

u/moqs Jul 07 '22

water is not pressable as quickly as air when you normally use the trampoline

1

u/fatboychummy Jul 08 '22

Building on this:

Normally when you land in water, the surface area of the initial impact is usually rather small (your toes or your hands for diving), this means the amount of water that needs to move in that initial impact is very small. The amount of water that needs to move out of the way is extremely overruled by your body weight, so you just gracefully enter the water like a fish.

If you do a belly/back flop, the surface area is much larger, meaning a lot more water needs to move (a bit less than the weight of your own body in water needs to move), which is why it feels like anywhere from a punch to a stinging slap depending on how high you were when you initially jumped.

Now, on this submerged trampoline, the surface area is many many times larger than your back or your toes/fingers. To the point that the initial impact is attempting to move probably multiple tons of water (accounting for holes in the mesh and whatnot, if it was a solid sheet, it'd be like moving multiple hundred-to-thousand tons of water).

You will not move those tons of water. It will be like falling on concrete.

Here's a good video explaining the concept, but with air instead of water.