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Balconies

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Apple
, November 30th, 2012 at 11:38 PM (2622 Views)
Say Jim is falling from a typical balcony (see image; he's too short and thus can't exert any forward momentum to make himself land safely in the balcony below, so he has to rely on his arm strength to catch the railing below him if he falls). Also, there is an obstacle on the floor of the balcony he is holding onto, so he can't pull himself up directly.

How much force must Jim's shoulders and fingers be able to withstand to catch a balcony one floor below the one he is falling from?

Of course accuracy (i.e Jim's ability to catch the railing on the balcony below him) comes into play as well, but just deal with the force section before we come to securing the catch's success.

I assume 1/2mv^2 + mgh (kinetic+gravitational energy formula) is involved, but I'm not entirely sure how to apply this. Which height do we apply, the difference between balconies or the distance from the ground?

Furthermore,what are the appropriate muscles that Jim should take to strengthen in order to be able to take the force of the impact when catching the railing? Lats are definitely a must, but I assume triceps also come into play. What other muscles are needed?

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On a separate note, I'm asking because I was watching this movie:

Apartment 1303 (1303大厦)

http://www.youtube.com/watch?v=zWvP4C4GjUA

1:31:42 is where she goes 'ohnoz' and the ghost kills her shortly afterward by forcing her to drop.

I know it's a horror movie, but in a real life scenario it looks like she could have just climbed down the silver railings, grabbed on to the white section and used her legs to swing her way into the apartment below.

After all, her body is long enough and her legs appear to extend far enough below the white section of the balcony to allow her to exert momentum and land safely within the balcony that she was clinging onto.

So I was thinking, 'what if the balcony is long enough that she can't use her legs to exert enough momentum?' Which brings us to the Jim scenario above. As you can see in the above scenario, Jim is cockblocked from exerting forwards momentum because the damn balcony's concrete section is too tall compared to his body. In such a situation, how should he ensure that he does not die?

Also, if you guys have any more efficient suggestions for how Jim could get out of his fix, mention them as well.

Updated December 1st, 2012 at 12:06 AM by Apple

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  1. RR121's Avatar
    He should rocket jump out of his predicament.

    Its clearly the best solution.
  2. Enhance's Avatar
    If you're serious about this task (reading further guess you are?), then basically good ol' Jim needs to decelerate himself from speed of falling to 0 in the brief time from when he starts applying force with his fingers on the balcony. If, say, he was falling for a second before that (speed when he touched fingers with balcony edge would be 10 m/s [actually 9.8... but who cares]), and he weighs m, and, say, time to full stop was roughly 0.2s (say, he stretched really slightly due to elasticity of his body for 0.2s), and for starters let's take fingertip force permanent (until he stops) - it means the acceleration in his case was -50 m/s^2. Adding permanent g, means he forced out a 60 m/s^2 acceleration with force of his fingertips - and thus the force (F=ma) stressing his fingertips was 60*m, and taking 60 kg as his weight it's 3600 J - equivalent to holding 360 kg weight.

    Of course, it's all rough numbers - but if Jim's flying down set of balconies he can't get into he should try slowing himself down gradually, grabbing all the balconies he flies past. Though in this case, he should take into account distance between balconies - if it's too far, it might not be worth it.

    Not sure if I'm totally accurate or right in this whole shit, but I'm tired and out of fucks.
    Updated December 1st, 2012 at 01:14 AM by Enhance
  3. Apple's Avatar
    Quote Originally Posted by Enhance
    If you're serious about this task (reading further guess you are?), then basically good ol' Jim needs to decelerate himself from speed of falling to 0 in the brief time from when he starts applying force with his fingers on the balcony. If, say, he was falling for a second before that (speed when he touched fingers with balcony edge would be 10 m/s [actually 9.8... but who cares]), and he weighs m, and, say, time to full stop was roughly 0.2s (say, he stretched really slightly due to elasticity of his body for 0.2s), and for starters let's take fingertip force permanent (until he stops) - it means the acceleration in his case was -50 m/s^2. Adding permanent g, means he forced out a 60 m/s^2 acceleration with force of his fingertips - and thus the force (F=ma) stressing his fingertips was 60*m, and taking 60 kg as his weight it's 3600 J - equivalent to holding 360 kg weight.

    Of course, it's all rough numbers - but if Jim's flying down set of balconies he can't get into he should try slowing himself down gradually, grabbing all the balconies he flies past. Though in this case, he should take into account distance between balconies - if it's too far, it might not be worth it.

    Not sure if I'm totally accurate or right in this whole shit, but I'm tired and out of fucks.
    You misunderstand. I mean how much force would his shoulders/body have to withstand when he catches the balcony rung just below (or 2-3 floor below) the rung he's hanging from, so he can pull himself up from there. Assuming that whoever pushed him over is still waiting on the floor he's hanging from.

    And I am dead serious, you never know when some madman might push you over railings. >_>" Especially with all the TV shows with villains threatening to throw people off of buildings giving them ideas.
  4. Enhance's Avatar
    Where's the part I misunderstand? I broke down a situation where the guy is falling with speed of 10 m/s catching the railing of a balcony. If you release the reel of balcony you were pushed off and catch the one two levels below, you'd be flying at around that speed.

    The part that is hardest to measure would be the "0.2s" one, time to full stop. It is also the part you might try to enlenghten if you were Jim - use your hands as a small spring to make it last longer. I think you misunderstood me up there too.
  5. Reekwind's Avatar
    That's like trying to count your current output with the ideal resitivity which is ∞

    he could catch by pure luck or with having skils of an aged parkour jumper...