– How do divers dive from like 170 some feet in the air and have zero damage, but if someone jumps off the Golden Gate Bridge, they are probably going to die.
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When you hit water from a dive the forces on you are related to how fast you decelerate on entry to the water, and the rate you decelerate is related to how fast you’re going when you hit the water. More speed = more force = more injury.
The Golden Gate Bridge is about another ~70 feet higher than the world record high dive.
The additional speed you pick up from that additional fall distance is enough that the deceleration forces upon impact with the water become high enough that even an ideal dive would result in severe, and life threatening, injuries.
The force involved here is because the faster you hit the water the faster you have to accelerate a volume of water about equal to your own volume and push it out of the way to make space for your own volume to enter the water. If you weigh, say, 150 lbs then you’re gonna need to push 150 lbs of water out of the way in the time it takes for you to enter the water, except that water is all surrounded by other water that you also need to push out of the way. It takes a lot of effort to push all that water any noticeable distance in the ~0.05 seconds it takes for your body to fully enter the water after jumping from the Golden Gate Bridge, that work is performed by your body decelerating at something like 20g (or more depending how you hit) to transfer energy from you to the water. This is a force that’s very difficult for a person to survive being exposed to.
Note: despite popular mythology the water tension is a trivial portion of this, or you’d be able to make the dive safely just by putting a few drops of washing detergent on the surface.
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