Does Standing on a Chair & Jumping Affect the Force Felt by the Floor?

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Discussion Overview

The discussion centers on the effects of jumping from a chair on the force experienced by the floor, specifically examining whether bending the knees during landing alters the force felt by the floor. The scope includes conceptual reasoning and application of Newton's laws.

Discussion Character

  • Conceptual clarification, Debate/contested, Technical explanation

Main Points Raised

  • One participant suggests that the floor feels the same force regardless of whether the jumper bends their knees, attributing this to Newton's 2nd law.
  • Another participant argues that bending the knees reduces the force on the floor by allowing for a more gradual stop, thus decreasing deceleration.
  • A different viewpoint states that while the total force may be the same, bending the knees results in a longer duration of force application, leading to a lower peak force on impact.
  • Some participants question the terminology used, suggesting that terms like impulse or energy might be more appropriate than "total force," and emphasize that the force is indeed reduced when bending the knees.

Areas of Agreement / Disagreement

Participants express differing views on whether the force felt by the floor is the same or reduced when bending the knees, indicating a lack of consensus on the matter.

Contextual Notes

Participants reference concepts such as impulse, energy, and the role of time in force application, but there are unresolved definitions and assumptions regarding the terms used in the discussion.

Who May Find This Useful

Individuals interested in physics concepts related to force, motion, and the application of Newton's laws may find this discussion relevant.

Fischler
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If a person is standing on a chair and jumps off, does the floor feel the same force whether the person bends their knees or not?

I suspect the floor feels the same force regardless, as the energy felt by the body is absorbed by the muscles, but the floor feels the same equal and opposite force. I see this as Newtons's 2nd law. thanks!
 
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Then there wouldn't be much point in bending your knees!

The force on floor depends on your mass and how quickly you stop F = ma
By bending your knees your legs act like a spring and allow you to stop more gradually - since the deceleration is less, the force on the floor and so on you is less
 
The floor would feel the same total force regardless of weather you bent your knees or not as you land on the floor. The key factor here is time. If you bend your knees when you land there is less force felt on the floor for a longer time. If you don't bend your knees there is a larger force felt on the floor for a very short time. Albeit some might argue that the resulting pain from such an endeavor would be felt for quite some time afterwards.
 
The total energy into the floor is the same - but the peak force is less.
 
MrScience101 said:
The floor would feel the same total force regardless of weather you bent your knees or not as you land on the floor.

What on Earth do you mean by total force? Perhaps impulse or maybe energy are the words you're looking for?

And the force would definitely be reduced. The initial momentum and energy would be the same, but the force would act over a longer amount of time thus the force would be reduced.
 

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