Is it physically possible to climb up a building like this?

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    Building Physics
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Discussion Overview

The discussion centers around the physical feasibility of a person climbing up a building by jumping between two opposing walls, as demonstrated in a video. Participants explore the mechanics involved, including friction, force, and speed, while expressing varying degrees of skepticism and belief in the possibility of such an action.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant expresses doubt about the possibility of climbing the building, citing a lack of calculations and uncertainty about the required friction force.
  • Another participant believes that it is indeed possible, suggesting that some individuals can perform remarkable feats.
  • A participant questions whether calculations have been made to support the claims about force and speed requirements.
  • A later reply provides a mathematical analysis, suggesting that the average friction force needed would be proportional to the jumper's weight and that the required speed could be calculated based on the coefficient of friction.
  • The calculations indicate that with a static friction coefficient of 1, a speed of 4.4 m/s would be necessary, while a coefficient of 2 would reduce the required speed to 2.2 m/s, which seems more achievable.

Areas of Agreement / Disagreement

Participants do not reach a consensus on the feasibility of the climbing method, with some expressing belief in its possibility while others remain skeptical and highlight the need for more calculations and evidence.

Contextual Notes

The discussion includes assumptions about the coefficient of friction and the dynamics of jumping, which are not fully resolved. The calculations presented depend on specific values that may vary in real-world scenarios.

CamSpell
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In this 19 sec. video, a guy climbs up a building by jumping against two opposing walls. I don't see how that could be possible. Some shoe-soles materials stick very well on smooth-shiny surfaces, true!, and the guy's mass has a side-to-side motion and less time to fall down... But I still can't believe it's possible.

I haven't done the calculations, I don't know how to do that, and we don't even know what the actual friction force is. But judging by how it looks I would say more force / speed should be required to defy gravity. It's just an uneducated approximation.

What do you think?
 
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I think it is possible.
some people can do some amazing things.
This is one of them I believe.
 
CamSpell said:
It should require more force, and more speed.
Have you calculated it?
 
CamSpell said:
What do you think?

When you see what others can do:

 
A.T. said:
Have you calculated it?
...
Nope!, I wouldn't know how to calculate it. If I knew how to do that I wouldn't have asked. It's just an opinion of mine, an approximation judging by how it looks. I'll rephrase that in the original message.
 
While you are doing this, the wall should provide an average upwards friction force of mg. This needs an average normal force of
\frac {m g } { \mu}
The average horizontal acceleration is \frac { 2 v } { T } = \frac { g } { \mu}
(the average of the absolute value of course, and you accelerate from -v to +v and back.)
This gives a required speed of:
\frac {g T} {2 \mu }
I get T = 0.9 from the video (8 jumps in 7 seconds). The static friction coefficient is probably at least one, but might be as high as 2 (found rubber on glass)
with μ=1 you get v = 4.4 m/s. That's the maximum speed. It's hard to get the speed from the video, since all body parts will move at different speeds, and the jumper is in contact with one of the walls and accelerating most of the time.
Since the walls are only about 2m apart, and the the time taken is 0.9 s for each jump, v = 4.4 m/s seems too high for the maximum speed, so I think a μ significantly bigger than one is needed. With μ=2 the maximum speed only has to be 2.2 m/s, which seems very possible.
 

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