Obviously I know hitting the surface of water flatly would be lethal but you should be able to stay relatively unharmed if you jump like divers do.
In: Physics
There are a lot of bridges people jump from for sport regularly, and they come out perfectly healthy. If you’re thinking “suicide bridges” like the golden gate bridge, it’s a combination of extreme height (20-30 meter drive is ok, 70+ meters isn’t), cold water, far distance to the next land, and strong currents that is deadly. One might be killed by the impact alone at that height, and it that’s not the case, it’s drowning with extra steps.
No it’s still lethal if you dive in. From that height it’s like hitting something solid. If you don’t break your neck there is a good chance it will knock you out and then you will drown.
Simply put, a matter of energy and resistance.
Many different matter have different density, viscosity, etc.
When something reach a liquid, they need to break the surface and move water. Simple rule: You can’t be somewhere where there is no room. So you need to move things. When you jump in water, some of your energy is transferred to the water to make it move. When you jump like a diver, you move less water at a time. You only move a bit of water every milliseconds. As a result, you need only minimal energy to do so. (important for part 2: The amount of energy sent to try and split water)
On the other hand, when you jump and land flat, you’re trying to move a LOT more water at the same time, which mean a LOT more energy spent trying to move it every milliseconds.
And in here come’s Newton’s 3rd law: “Every action has an equal and opposite reaction”. That’s where the problem lies. When you break the water surface, you take as strong a shock than the water. By boing diver style, you slowly ramp up the amount of energy needed, by doses that your body can take without breaking. When doing a flat, you go from 0 to 100 almost immediatly taking a very strong backlash, potentially stronger than your body can afford.
Now that we know why this happen, it’s quite simple to understand why jumping from too high is lethal: By jumping from higher, you can go faster (until terminal velocity). Going faster means more energy. More energy mean more backlash. The same issue as the first case, but rather than taking more energy because you’re diving poorly, you simply increased the total initial energy so much that even doing things correctly doesn’t diffuse the energy enough.
while the human body is mostly insensitive it “speed”, we feel changes in velocity quite badly,
n the case of these jumps is going from Near Terminal velocity to zero in a split second(hitting the water at such speeds is effectively going head 1st into a wall that wont give in).
if the impact alone doesn’t break your neck you will very likely knock yourself out or injure yourself just badly enough that you couldn’t leave water by yourself and you’d drown.
Have you ever swirled your finger around a pool of water, pretty easy right? Have you ever tried to swim with a nice fast stroke, that’s a lot harder right? If you give the water time to move, it’ll move around you quite nicely. If you try to force it aside, it’ll resist and you’ll need to use more strength.
It takes force to move water. The more water you’re trying to move or the faster you try to move it, the more force it’ll take.
If you’re hitting the water at a terminal velocity or something approaching it, that water isn’t moving in a hurry. Since the water isn’t moving aside for you much, you’re going to have a really hard landing. A bone-breaking, organ rupturing landing.
And if you don’t die on impact, now you’re in the water with a body that’s in no shape to swim.
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