ELI5: Jumping off a bridge to water

Submitted by Future_Carrot3124 t3_z48r3q in explainlikeimfive

Why often in the movies or series, or multiple incidents you can find on the internet, people that want to commit suicide are trying to jump off a bridge to water? How does it supposed to take their life excluding of course the case when they can't swim and would just drown. There are many videos where people jump off a cliff to water just for fun and everything turns out fine, so why and how jumping off a bridge is supposed to kill you if you just can swim?

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Calvinjamesscott t1_ixq934w wrote

Water has a lot of mass and surface tension. When you hit it at velocity, the g's from the impact can be fatal. People who cliff dive purposely land with a very narrow profile to minimize the force of the impact.

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JustTrixxy t1_ixqawkh wrote

Workers on the Golden Gate Bridge always kept their toolbelts loose and quickly detachable so if the fell, they could throw it while falling to break the tension, thus saving them for the surface splat

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PM_ME_A_PLANE_TICKET t1_ixqik6k wrote

This sounds like the kind of thing that's completely made up, but nobody can really disprove.

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km89 t1_ixqkwhm wrote

It is, but it's not un-disprovable. Mythbusters did this and found that it doesn't really help. The tools break the surface tension, but the surface tension isn't the only factor, and the water still hits you like a truck.

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Target880 t1_ixq9ktc wrote

To feel the forces of the water do a belly flop by jumping from just above the water's surface and you will notice the water can have quite a high force on you and take time to move away

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mb34i t1_ixqg5p2 wrote

Water "takes a while" to move out of the way of an object that impacts it. And gravity accelerates you quite strongly on your way down, so from higher bridges you'll have quite a bit more speed than from lower bridges.

So bottom line, the faster you go, the more water will feel like a thick syrup, very slow to get out of your way and make room for your body, compared to your speed. The impact with the surface feels more and more like an actual impact, like hitting a solid surface. Such impacts cause fractures and internal damage, you can die from them.

Just to give you an idea, we do this with AIR too, that's what an explosion is. You can see an explosion's spherical shock wave, that is a wall of air atoms that are moving so fast that they are not going to get "out of the way" of any object in their path. The shock wave is just air, but it impacts with enough force to destroy buildings and kill people.

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