# – Would I survive if I jumped off a collapsing building right before it hit the ground?

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Curious as to what would happen if I perfectly time it. Would I be safe? Lets say the building is 4 stories high

In: Physics

If you were able to jump 4 stories high in one leap you would be unscathed, seeing how most people aren’t able to do that, you would likely die.

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Somebody who has taken physics can do the exact science, but to put it in terms I understand:

– Building is falling DOWN at a speed of FAST AS FUCK
– You jump UP at a speed of SLOW AS FUCK

So, I don’t think the slow as fuck speed directed up is going to counteract the fast as fuck speed directed downwards very much.

So your example is problematic because a four story fall is not a guaranteed death sentence. Plenty of people have survived falls from that height, hell we’ve had several people jump from the upper deck or fifth floor, parking garage at the airport. I used to work at and some of them survived although for how long I don’t know.

That said jumping would accomplish nothing. You’d still be moving toward the ground because of gravity, your legs aren’t strong enough to come anywhere close to matching your speed of descent. Even if you did, somehow managed to time it perfectly you would hit the ground going basically as fast as you would have doing nothing.

Trying to jump off and go horizontal would either resulting you going nowhere or are you going a very small distance but still accelerating toward the ground at the same rate you were.

No. The reason has to do with potential energy versus kinetic energy. As you stand at the top of the building, gravity imparts to you a certain amount of potential energy. It keeps that form as long as you remain that high up. If you take an elevetor or climb down, that potential energy is converted to kinetic energy as you descend. What makes elevators and climbing safe is that the conversion happens slowly. Your body can take slow changes of this kind pretty well.

When the building collapses, the potential energy begins to convert to kinetic energy. But now there’s no elevator or rope or whatever, so the conversion happens quickly. When you hit the ground, the kinetic energy all dissipates at once, and some of that goes into the ground, but most of it splatters you all over the place.

If you jump just before you hit the bottom, you will convert some of that kinetic energy back into potential energy. But there are two problems with this. The second problem is that you will still need something to grab onto or otherwise support you: without that, you will just start falling again.

But the bigger problem is that you can’t really dissipate enough kinetic energy this way to make a difference. This isn’t to say that it’s totally imposssible, but to convert *all* of the kinetic energy back to potential energy, you’d need to be able to jump all the way back up to your original altitude. If that was four stories up, you just can’t jump that high.

Unless you are talking about you would survive anyway other then being burried by rubble and the jumping is about getting away from the rubble, no it doesnt realy make a diffrence. Its the same thing as jumping in a free falling elevator befor it hits the ground. While you are jumping you are still falling down it might not look like you do because the elevator/building is further away but relative to the ground you are still falling the whole time and are still accelerating the whole time.

for simplicity lets say

4 stories = 40 ft

you can jump ~2ft

if you perfectly time your jump, ignoring specific calculations, you’ll hit the ground at a speed as if you had fallen from somewhere between 38-40 ft instead of exactly 40 ft

so still immensely painful