Cable that holds the elevator got disconnected

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In the scenario of an elevator cable disconnecting, jumping just before impact would not save a person from injury or death. Human legs cannot generate the necessary force to counteract the fall speed, and even if a jump could slightly reduce impact velocity, it would not be enough to prevent severe harm. The elevator's descent would reach terminal velocity quickly, and occupants would experience free fall, making it difficult to time a jump effectively. Safety mechanisms in elevators are designed to prevent full drops, making such scenarios rare. Ultimately, the consensus is that jumping in this situation would not significantly improve survival chances.
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say u r in a elevator, and suddenly the cable that holds the elevator got disconnected and u r falling to the ground while standing,and dropping really fast from 15th floor. you would die right ?

this is the question.. just before the elevator crashes on the surface
what if you jump ? would you get hurt ?
 
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That would be an understatement; unless you can jump 60 miles per hour(at the right moment). You could scream for approximately 3 seconds or so. It probably wouldn't do any good, but you'd have nothing better to do anyway.
 
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Right idea, but human legs can't generate nearly enough power to keep you alive. However, you would hit the ground going slower than if you had not jumped; just not "slower enough".
 
There is a possibility that the elevator could slow enough as it got closer to ground zero. This would depend of how quickly the air beneath it could escape. You could conceivably walk away from this kind of scenerio. The elevator would reach terminal velocity rather quickly. As it dropped the pressure beneath it would increase as it got closer to ground zero. Again this is entirely dependent on how quickly the air beneath the elevator can escape. Under the right conditions it could be like landing on a big pillow.
 
Interesting idea. I wouldn't recommend that you demonstrate it without changing the current design that is commonly used.
 
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it is possible, but if the lift is falling at 60 mph, you then have to jump up at 60 mph. (like that other guy said)

but also, you'd proberly then smash your head on the roof.
 
It just goes to show you; if it's not one thing, it's another. I've spent a lot of years skydiving. Most people seem to prefer screaming; I certainly do. -Mike
 
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Next time you see me in an elevator with a matress, I guess you'll know why... if the cable snaps, maybe I will quickly lay spread eagle on the matress.
 
I'm not sure I have ever read an article about an elevator cable snapping, and other safety features failing also, where the elevator actually does a full drop. The safety features must be pretty failsafe.
Back to the original question - Would you die?
I would much rather fall 15 stories in an elevator than a full gainer to street pavement. Would you die though in an elevator? Parameters would have to be set to answer that question. How big is the elevator? How much does it weigh? How well sealed is the shaft? How much space is there between the elevator exterior to the shaft walls? If you poop in your pants and have a heart attack - Does that count as an elevator fatality?
 
  • #10
I was in an elevator "crash". They never would tell me exactly what the cause was.

When I stepped into the elevator, there was a muffled "explosion", the elevator started dropping and then the saftey mechanism must've kicked in which caused the elevater to stop with such a violent jolt that the suspended ceiling collapsed including the metal support beams. I got banged up and cut, but nothing serious.

Long story short, I was trapped for almost two hours between floors. Everytime I moved, the elevator would rock back and forth. They had to have a crew go to the roof, through the shaft and attach a cable to the elevator and manually pull the elevator up.

So, there is some kind of safety cable.
 
  • #12
also there's meant to be springs and dampers at the bottom of the shaft.
 
  • #13
I have seen skydiving and construction accidents that have caused horrific injuries. You may not die, but chances are that you will probably wish you had.
 
  • #14
how can you jump at the right moment when you're on the ceiling?

you are lighter than the elevator so it'd be might hard to get to the elevator floor in ~10seconds
 
  • #15
Originally posted by Michael D. Sewell
I have seen skydiving and construction accidents that have caused horrific injuries. You may not die, but chances are that you will probably wish you had.

Skydiving accidencts such as hook turns? Those damned front risers turns, man they cause so much crap.
 
  • #16
*kindly points out to ipx`vortex that just because something is heavyer, doesn't mean it falls faster, and that a 20 ton weight would fall at the same speed as an egg, and they would land at the same time*
 
  • #17
No one has yet mentioned that, given there are no safety mechanisms in place and that the elevator is in a free fall condition, the occupants would also be in a free fall condition. Therefore the occupants are essentially weightless, how do you jump when you are falling? If you did manage to push off of the floor of elevator it would only effect when you stopped, not how fast you are going when the sudden stop occurs.

So, in summary, No jumping would not save you.
 
  • #18
Do you suppose the terminal velocity of the elevator would be the same or greater than the terminal velocity of the occupant in the elevator? I don't know--I've never seen an elevator fall.

cookiemonster
 
  • #19
I doubt that the elevator would have time to reach terminal velocity unless the shaft were nearly air tight, then its fall would be considerable restricted. Since the occupants travel in a bubble of still air they would not be subject to forces which create a terminal velocity. Their rate of fall would be the same as the elevators. If the rate of fall of the elevator were restricted then the occupants could get a very good jump off the bottom as their "weight" would be be m(g-r) where r is the acceleration of the elevator.

The fact remains that the jump would only effect when they hit, not their velocity when they do hit.
 
  • #20
aychamo,
Nobody else here knows about front riser turns, so we should probably skip it for now. Maybe you could start a skydiving thread in the lounge. DOOR! Blue skies, black death. -Mike USPA B-16564

To the rest of you,
M.I.T. and R.P.I. have both had skydiving teams, and have both produced many fine jumpers. I have jumped with many very bright students and grads. Some of them have gotten themselves in some pretty bad situations. It wasn't always a happy ending. You guys have some very interesting ideas, but I assure you, the screaming method seems to be very popular among people trained in physics. In some cases it is as productive as anything else. -Mike

P.S. I never jumped with an egg, but I jumped with a girl who weighed about 20 tons (more or less). She fell really fast!
 
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  • #21
I'll never understand why people jump out of a perfectly good plane.

cookiemonster
 
  • #22
Because the door is open.
 
  • #23
I don't get it.

cookiemonster
 
  • #24
We're getting off subject(my fault). Life is like Indy,
250,000 spectators and 33 drivers. Enjoy your hot dog. -Mike
 
  • #25
Originally posted by cookiemonster
I don't get it.

cookiemonster
FUN. The adrenaline shock so strong that after I landed from my 1 and only jump, I was shaking for like 15 minutes afterwards and had to sit down to avoid falling down. I've never had a rush anywhere close to it (never done drugs).
 
  • #26
I assume that each floor is 2.5 meters high, then negleting the force of the air under the elevator(well, i don't known whether it is possible to neglect), you'll hit ground with a speed of 25 m/s.As far as I know human body can resist 25G downward. then if it takes longer then 0.11 seconds you'll probably survive.
 
  • #27
Survived 3 malfuctions, the first one was a high speed total malfunction. The other 2 were slow rate of descent but much angular momentum. I dealt with each the same:
1.) screamed
2.) found Jesus(alternates are acceptable for other cultures)
3.) pulled appropriate rip-cords/untied 40 million knots(fast)

In the elevator, I doubt one would get any further then #2 before impact. -Mike
 
  • #28
1.) Run the numbers again, you will find that mine are good given the information available.

2.) You demonstrate, I'll take side bets.

3.)I will use the money to put flowers on the graves of my former friends who fell to their deaths under malfunctions that were going slower than the elevator example.

Believe me, you do not want to hit the dirt going 60 MPH. It's really ugly. -Mike
 
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  • #30
Nope.
 
  • #31
Michael D. Sewell, even if she did way 20 tons, she'll fall just as fast as you. in fact, she'll proberly fall slower, due to less areodynamic ability.

and i forgot about the for ever action there's an equal and opersite reaction. so if the lift is falling at 60 mph you need to jump up at 120 mph.
 
  • #32
Gara,
Maybe the 20 tons was a bit of an exageration. I have broad shoulders and a slender build, consequently my terminal velocity is about 10 MPH or so slower than most of the other jumpers. Most of the jumpers that have a similar build wear weights and very slick, tight jump suits. Heavy people generally have a ratio of weight/surface area that is greater than thin people, so they fall a lot faster. One time we had a bunch of weight lifters(obvious steroid cases) show up. Boy, they really had a high rate of fall! The jumpmasters had a difficult time keeping up with them. All of them "hammered in" on landing too.
A simple "rule of thumb" that we give students with respect to freefall times is: ten seconds for the first 1000 feet, five additional seconds for each remaining 1000 feet.
I hope this gives you a better understanding of weight, gravity and aerodynamic drag. -Mike

P.S. Hitting the ceiling of the elevator going 120 MPH doesn't strike me(pardon the pun) as being a viable alternative.
 
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  • #33
well the 20 ton metal and an egg would fall and hit the ground on the same time

but i don't think it would happen cause of the air resistance
if there wasnt they would probably land at the same time
 
  • #34
aye that's what I am trying to tell him. yet he seems to believe heavyer things fall faster. o_O

and yes, jumping up at 120 mph would stop you from dieing from the fall of the lift, but presents a new, head smoosh style, problem.
 
  • #35
What one believes or does not believe has no effect on the laws of physics. If by metal you mean a sphere of solid steel, you are wrong. Steel has a density of 490 Pounds per cubic foot. The density of an egg is not much different than the density of water(62.4 pounds per cubic foot). You can easily check this by placing an egg in a pan of water. What you are missing here is we call in ballistics SECTIONAL DENSITY. I assure you that a block of steel has a much higher terminal velocity than an egg, and would go past it in free fall like a pay car by a tramp.

Acceleration as a function of time
a = g(e^-bt/m)

b = mg/terminal velocity

Integrate this and you will get instantaneous velocity.
Integrate again and you will get the displacement.
-Mike
 
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  • #36
Originally posted by Gara
and yes, jumping up at 120 mph would stop you from dieing from the fall of the lift, but presents a new, head smoosh style, problem.

unless you had exceptional timing! 7..6..5..4..3..2..ONE!

Cliff
 
  • #37
if you jumped up a lift at 120mph, you have to remember the roof of the lift is about 7 foot high. unless you can slow down after the very moment you jump, you're going to hit the roof :)
 
  • #38
But if you jumped up so that you reached 120MPH relative to the elevator right at the moment of impact, your velocity would be zero relative to the ground.

Besides the roof maybe hitting you as it decelerates (assuming it decelerates differently from the floor as the elevator buckles from the impact) you would be, in effect, simply standing on a crumbling floor. And if you have the timing plus incredible strength (and luck) like that, you should run out and buy a lottery ticket, maybe just after kissing the ground and saying a couple prayers...:smile:

Cliff
 
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  • #39
then what about if you weren't in the elevator but on top of it. what happens if you jump off it just before it hits the ground? would you survive?
 
  • #40
One more time.

Jumping will not save you. If you could jump in a free fall (it is not clear to me how you would do this!)you will not change your final velocity. In fact, if the elevator where being slowed by some mechanism which would then enable you to jump, you would hit the ground at a HIGHER speed then if you had stayed with the elevator. This because during the time of your jump the elevator will have fallen some distance, you will have to fall that extra distance and will have a longer time of acceleration, thus a HIGHER VELOCITY when you finally hit the ground. How will this help you?

Consider this, if the elevator is going down at its normal rate you can jump up and down as much as you like, each time you will land back on the elevator, since the elevator is moving you will have to be falling FASTER then the elevator in order to catch up to it after you jump. This will be true even if the brakes fail and elevator is accelerating at some rate less then g.

So in summary now only will jumping not help it will only serve to INCREASE the speed at which you hit bottom.
 
  • #41
i don't think so. if the lift is falling at 30 mph, and you jump up at a speed so you are now at 0 mph, you will hang there and then gravity will take over again, and you will fall, but for only the distance between you and the floor, which if timed right, should be about 1 foot.

but i must say again, you have a high chance of living by staying in the lift because at the bottom of lift shafts are springs and dampers to make for a soft landing in the event of a lift cable failing.
 
  • #42
Originally posted by Gara
i don't think so.

Integral,
Some peoples haids is hardern chinese arithmetic. Godspeed, good luck, and god bless.
-Mike

P.S. Run away! Run away!
 
  • #43
i don't think so. if the lift is falling at 30 mph, and you jump up at a speed so you are now at 0 mph, you will hang there and then gravity will take over again, and you will fall, but for only the distance between you and the floor, which if timed right, should be about 1 foot.

Gara, Gara, Gara...

It is not your speed relative to the elevator which is the problem. The only speed that matters is your speed with respect to the ground. What looks like a jump inside the elevator is not seen as a jump from the ground outside the elevator. If the passengers speed with respect to the elevator were of significance then why jump, you are not falling at all, but standing very peacefully on the elevator floor.
 
  • #44
I do believe Integral is wrong here. Assuming you had a super human pair of legs - You could time a jump with the proper force to where it would seem as if nothing happened. Thats of course if the elevator doesn't bounce on impact.

The elevator will eventually attain terminal velocity due to air pressure and whatever drag it may encounter. You on the other hand are not subject to these effects, and will fall at the rate specified by gravity alone. You could have a scale in the elevator and find that you weigh at least something - be it one pound, or maybe even ten. Whatever the number - You can push off of the elevator. It's just a matter of transferring the energy from you to the elevator. The elevator will get a sudden boost in speed, and if timed right with the proper force - you will only hear a very loud noise.
 
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  • #45
Assuming you had a super human pair of legs

And if pigs had wings they could fly.

Even with a super human (how stupid can it get!)legs, you will not change the speed at the time of impact. As I said in a previous post (Did you bother reading them?) if the elevator is not in a free fall situation, a jump, ANY JUMP will only serve to increase your speed at impact. There is NO way that you will hit any slower then the speed of the elevator. Remember that old rule, any thing which goes up must come down. You can jump but you have to land.
 
  • #46
Integral
You are flat out without a doubt ---- wrong!

I suggest you start reading some books, and come back when you got it figured out, so you can say you had it flat out without a doubt ---- wrong!.

Next thing yer going to tell me is that if I fired a bullet straight up in a falling elevator - It would never get out of the barrel. Your fantasy world does not exist.
 
  • #47
Originally posted by Integral
And if pigs had wings they could fly.
Which means they might survive the elevator crash unharmed as opposed to the jumping humans.
 
  • #48
Which means they might survive the elevator crash unharmed as opposed to the jumping humans.
A flying pig would have to flap those wings double time at ground zero, but yeah - A flying pig could pull it off too if their wings could handle the stress. How much stress can a flying pigs wings handle anyway?
 
  • #49
Originally posted by UltraPi1
Integral
You are flat out without a doubt ---- wrong!

I suggest you start reading some books, and come back when you got it figured out, so you can say you had it flat out without a doubt ---- wrong!.

Next thing yer going to tell me is that if I fired a bullet straight up in a falling elevator - It would never get out of the barrel. Your fantasy world does not exist.

Physics please?

Can you keep it close to the topic?

Back up your words with physics or do not post. Further off topic noise will simply be deleted.
 
  • #50
Originally posted by Integral
Gara, Gara, Gara...

It is not your speed relative to the elevator which is the problem. The only speed that matters is your speed with respect to the ground. What looks like a jump inside the elevator is not seen as a jump from the ground outside the elevator. If the passengers speed with respect to the elevator were of significance then why jump, you are not falling at all, but standing very peacefully on the elevator floor.

Even when your body is in the act of flying upwards while jumping inside of the falling elevator, this speed is simply subtracted from the speed that the elevator is falilng,, so you would ultimately still be falling down very fast.
 

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