If you’re in an elevator that is falling, could you jump right before and not get injured?

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So if you time it perfectly, the elevator would hit the floor but since you were in the air, you don’t feel the pressure of the landing. And then you wouldn’t get injured, right?

In: Physics

No, you would just hit the floor a split second later with *maybe* slightly less force than you would have had you not jumped. You get hurt by a sudden stop, it doesn’t matter if that sudden stop was from the elevator itself suddenly stopping (not jumping) or you hitting an elevator that has already stopped (what happens if you jump)

It would be virtually the same.

You would still be traveling as fast as the elevator, you would just hit a split second later.

I was literally just thinking about this an hour or two ago. You have to lie down on the floor.

Long answer: Maybe think of it like that if you where to jump out of a flying plane and while you’re falling someone would construct an elevator around you, do you think that would in any way change the fact that you’re falling and thus building up some pretty high velocity that is suddenly changed to 0 once you hit the ground?

Depends on how fast your falling, if your falling really fast, it’s not gonna matter because you are going to slam into the ceiling and then the floor, maybe with less force

You’d still be falling at mostly the same speed as the elevator. You’re probably falling downwards much faster than you can jump upwards, so if you could jump up, you’re only reducing your downwards motion by a fraction. So, you’d jump up and hit the ground a fraction of a second later, at maybe 5 mph slower.

*Also, if the elevator and you are both in free-fall, it’s going to be harder to put full force behind a jump, since there’s no force pushing your feet against the floor.

If the elevator started falling from any more than a single story high, no. The speed the elevator is falling is far too high to overcome with your jump. For example, if you would normally hit at 40 MPH and countered with a 3 MPH jump, you’re still smacking into the ground at 37 MPH which will not end well for you.

Imagine driving 50mph into a brick wall with your feet on the dash, and push back at the last minute. You already have too much momentum going forward, and the vehicle you are in will be crushed anyway.

Mythbusters tested this in one of their early episodes. The crash test dummy they used got absolutely destroyed I seem to remember. I’m sure you can find the episode somewhere online

Edit: it’s ep 17

If you jump up in a fallen elevator you are not moving upward relative to the ground. You will just be moving down slightly slower.

A simple way to compare how you can jump versus the acceleration that gravity provides is to stretch your hand up and touch a point as high as you can on the wall or on something else. Then jump up from standing still and see how much higher you can reach with your hand. I think for most people it will be less than half a meter.

That is the height you can jump, you can jump on to or over higher stuff but a large part is just that you bend your legs up.

What limits the height you can jump from is gravity. So you jumping in an elevator world compensate for a fall from the height you can jump. So we talk about reducing the elevator drop by 0.5 meters.

I suspect the best to do if you were in a falling elevator is to manage to lay down on your back flat on the floors so you can spread out the force on as large an area as possible. So jumping is a bad idea,

Elevators do not fall that way you see in movies. There are systems that automatically brake if a cable snaps. It was in fact the invitation of the safety elevator the stop if the wire break that startedd the usage in buildings. Elisha Otis demonstrates the invention in 1854 and it as the start of the modern elevator business.

You would have to jump with a force that would accelerate you upwards to the same velocity as the elevator…..which is impossible. The g-force would then probably turn you to jam instead of the impact. Its all about conservation of energy really.

In theory you could reduce the impact slightly.

In reality it has been shown that the reduction in impact would be very slight, and not enough to offset the other issues of the technique.

For example you would need to time your jump with split second perfection, while in an enclosed box with no point of reference to tell you when the impact will be – jump slightly to early or late and you will increase the impact force and hurt yourself more.
By jumping you also risk striking the roof of the elevator as it stops from the impact, or getting thrown around if it doesn’t stop evenly.

Instead, lay flat on the floor so the impact is spread over your whole body rather than directed completely through your ankles and legs, and relax so that your body is loose and more able to absorb the impact without damage.

In reality it is also notable that it is incredibly unlikely an elevator will ever fail so critically. They come with multiple failsafes to prevent a fall such as multiple redundancy in the cables that support the car, automatic brakes to stop the car in the event of a free fall, and the fact that an enclosed lift shaft can actually act like an air piston to slow the car as it reaches the bottom.

Others have talked about how your speed change would be minimal but there is another reason jumping would make things worse.

At the bottom of the elevator shaft there are shock absorbers. These make the transition from full speed to zero spread out over time. Without the shock absorbers, the elevator (and you) would go from 100 mph (or whatever) to zero in let’s say a millisecond – that’s around 5000g’s, which would kill you. If that deceleration is spread over a second, it’s only 5 g’s which is much more survivable. (I made up the numbers but the principal is sound).

If you jump before hitting the ground, you lose the benefit of the shock absorbers. The elevator comes to a stop and then you hit it all in one go.

This is the same reason, by the way, that it is important to attach car baby seats tightly, and tighten the belts around the baby snugly – in case of a crash, you want the “gradual” slowdown provided by the car’s crumple zones to be transferred to the baby.

If you can jump with enough force to match the speed of the falling elevator, yes.

That does mean, though, that your legs would have to accelerate you at the same speed that they’d have to absorb in the crash, which only means that you’d kill yourself rather than wait for the impact to do it…