Calculating the Spring Constant for Bungee Jumping

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Discussion Overview

The discussion revolves around calculating the spring constant for a bungee jumping scenario using Hooke's Law. Participants explore the relationship between force, displacement, and energy transformations involved in bungee jumping, considering both theoretical and practical implications.

Discussion Character

  • Technical explanation
  • Mathematical reasoning
  • Debate/contested

Main Points Raised

  • One participant seeks assistance in determining the spring constant, noting their weight of 735N and the rope's doubling in length upon jumping.
  • Another participant clarifies that the spring constant (k) can be expressed as k = F/x, emphasizing the need for information on the rope's stretching.
  • A participant suggests that if the rope doubles in length under the applied force, then k could be calculated as k = 735N/L, where L is the original length of the rope.
  • There is a discussion about the relationship between force and displacement, with one participant confirming that the change in force is proportional to the change in displacement.
  • Participants explore the connection between elastic potential energy (EPE) and gravitational potential energy (GPE), questioning if the displacement x can be represented as L in the energy equations.
  • A warning is raised about impulsive forces acting on the bungee cord at the bottom of the jump, highlighting safety concerns related to cord breakages and the potential for fatalities.

Areas of Agreement / Disagreement

Participants express varying levels of understanding regarding the calculations and implications of the spring constant, with no consensus reached on the exact method or safety considerations involved in bungee jumping.

Contextual Notes

Limitations include the lack of specific information about the original length of the rope and the assumptions made regarding the relationship between forces and energy transformations during the jump.

wangking
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Hey, i need some help here
I'm trying to figure out the spring constant for bungee jump

Say, I'm 735N and the rope will apparently double in length when i jump off it.
I don't know the length of the rope thought.
but i do know it does have a spring constant.
How to find out is the spring constant using the Hooke's Law F=-KX

Please help :)
 
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oh, we are trying to find the N/m ratio
how could i do that
 
F= -k/x --> |k| = F/x you cannot find it without some information on its stretching. O I just read that it doubles in length.
 
The rope doubles in length when 735N is added, so does that mean that
k would be equal to 735N/the length of the rope.
k = 735 / L
 
yes. When it has doubled its length it has displaced L from it equilibrium position.
 
Thanks homie, so is the
(the change in F) proportional to (the change in x) = k
 
If i were using the f = k x equation, and then use
EPE formula = half k x squared
Which is also equal to GPE so could i say
mgh = half k x squared,
and is the x still L
 
wangking said:
If i were using the f = k x equation, and then use
EPE formula = half k x squared
Which is also equal to GPE so could i say
mgh = half k x squared,
and is the x still L

Yes, this is the point where all the kinetic energy was converted into elastic potential energy.
 
If this is more that just a thought exercise you should be aware that at the bottom of the jump impulsive forces equal to approximately twice your weight act on the bungee cord.

There have been fatalities due to cord breakages from this cause.

Anyone who has had dealings with rope rigging will be familiar with snatch forces.
 

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