Question:
If you jump up when an elevator starts to descend, will you bump your head on the ceiling?
gablueliner
2006-07-21 19:16:13 UTC
Most elevators have a 7' or 7.5' ceiling. If one could jump up just slightly just as the elevator starts its decent, will you bump your head? You would have to time it just right I'm sure. My wife says no, you won't bump your head, but I disagree.

Just for fun: Next time you get on an elevator filled with folks, make sure you're the last person to get on. When you step inside, don't spin around and face the doors. Keep facing the crowd and watch their reactions. They will all be quite nervous as you are doing something that's not usually done. I learned it in a class I attended and I tried it. It's a blast!
Sixteen answers:
freebird
2006-07-21 19:36:10 UTC
Technically, it's possible if you had a fast enough elevator (not likely). You'd have to jump before the elevator starts downward.



If you jump, say 1', and get high enough to get you within 6", the elevator would have to travel six inches down during the same period that you are upward bound. No public elevator travels anywhere near that speed, but it is theoretically possible. The higher you can jump upward, the slower the elevator would have to be to connect with your head. If you were three feet tall, and can jump within 1 inch of the ceiling, even a public elevator could wack you if you timed your jump right.



If you started to come down before the elevator started, the elevator would have to descend faster than gravity causes you to descend. In this event, everyone in the elevator would hit the ceiling.



Don't give up trying. A concussion is definitely worth it if you can prove your wife wrong. Or you can embarass her by wearing a helmet whenever you get in an elevator.
Ted K
2006-07-21 20:04:23 UTC
Gravity...the thing that keeps us grounded as the earth spins won't allow you to hit your head. (I've tried it over and over when I was a kid). However, if I'm not mistaken, unless the elevator drops like a rock...I would say yes, you're going to hit the ceiling.

The outcome isn't favorable. (Basement Floor)

Also the majority of all elevators are controlled by Programmable Logic Controllers or PLC's that regulate speed and tell it when to slow-down, speed-up or stop at the precise level on a floor so the people going in or out don't trip or fall from an elevator that didn't stop when it was supposed to stop.

They're still fun... especially when they're quick! (Don't press "UP" then jump!)
FILO
2006-07-22 00:52:51 UTC
Absolutely not! For you to bump your head when you jump up, the elevator has to be drop down faster than normal speed at the force pressure of equivalent to or higher than your weight. Any higher than that you would feel weightless, and eventually the faster the elevator descend you'd be forced down with it with your head bumped on the roof and buried at least a 100 ft into the ground.
mom2babycolin
2006-07-21 19:24:02 UTC
If it's acceleration is high at first, then yes you will. I've seen it. When I was a teenager my friend was in a car wreck. So a bunch of us went up to see her at the army hospital. The elevators there are notorious for being nauseatingly fast. There's a LOT of inertia with the start and stop. So one of my friends decides to jump when it goes down, and he ends up hitting his head on the ceiling and knocking the cover off the light.



LOL we all laughed and then got the heck out of there.
~!EVIL $
2006-07-22 00:27:11 UTC
no obvsly not unless the elevator is in the state of free fall i.e when the ropes are cut cuz the gravity keeps us grounded to the floor of elevator and unless ur in space this wont happen
kevin
2006-07-21 19:22:19 UTC
hope you didn't have dinner riding on this one. here goes... you will not bump your head because you'r moving at the same speed of the elevator..sorry. i love the idea, i think i'll try that monday.
Chi-Master-N-May
2006-07-21 19:19:40 UTC
some times, once i jumped and i bumped my head because the elavator moved fast , but now days ost elevators ive seen are slow and i jump all the time because it feels kool, but i odnt bump my h ead cause they so dam slow
jtrigoboff
2006-07-21 19:18:52 UTC
No because you have been propelled by the elevator downward, if anything, it is harder to jump and hit your head
udee79
2006-07-21 19:35:38 UTC
I say yes since a good jumper or tall person could do it without help. I think your vertval leap would increase about 20% so yes.
Grist
2006-07-21 19:38:25 UTC
Sounds like you have succeeded in bumping your head on more than one occasion.
Rock_N_Roll_Chicky
2006-07-21 19:19:43 UTC
nope but the elevator will shake ..just make sure you dont do it during working hours
Mervin McGee
2006-07-21 19:19:37 UTC
Ive tried this multiple times and its never happend
anonymous
2006-07-21 19:22:10 UTC
Unless you have the legs of a kangaroo, I would have to say no.

But, you said you tried it..........was it a blast to your head?
hysteria75
2006-07-21 19:18:56 UTC
Watch the myth busters episode where they busted that one. They concluded that you will probably die.
anonymous
2006-07-21 19:33:26 UTC
no. g-force has to be active for that to happen. thats jus like tossing a ball upwards in a car. it doesnt do anything.



http://360.yahoo.com/profile-XIHIV3U7dKMIVCGAefaIM3NiF4s-
martialmichael126
2006-07-21 19:19:40 UTC
No. And I've tried.


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