Potential energy of a shoelace

AI Thread Summary
The potential energy of a tied shoelace is influenced by factors such as the material composition, tightness of the knot, and the substrate's modulus of elasticity. Measuring the work required to untie the knot can provide insights into the energy stored, but the relationship is complicated by friction, which dissipates energy as heat. Some knots, like a Gordian knot, can require significantly more energy to untie than to tie, complicating the calculations. The discussion highlights the challenges in relating potential energy to the work done due to non-conservative forces. Overall, the experiment's complexity stems from the interplay of various physical properties and forces involved.
Rothiemurchus
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How much potential energy is stored in a tied shoelace?
 
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What's it made of? How tightly is it tied? What sort of substrate is it tied into, specifically with regard to modulus of elasticity in the area of the eglets? Getting the idea?
 
You can work this one out by measuring the work done it takes to undo the knot.

Anyone any ideas for doing this experiment? I suppose you could do it with a force-gauge.
 
christianjb said:
You can work this one out by measuring the work done it takes to undo the knot.
No. the two works are unrelated.
 
lpfr said:
No. the two works are unrelated.

How so?

I guess that it's nowhere near a conservative force field, so most of the work is done against friction, which ends up heating the shoe-lace.
 
christianjb said:
How so?

I guess that it's nowhere near a conservative force field, so most of the work is done against friction, which ends up heating the shoe-lace.

You have answered yourself.

Have you ever heard about a "gordian knot"? Some real life knots are almost gordian. They ask for very much work to untie than to tie.
 
are you including energy stored as mass?
 
I don't know whe you are asking. Anyway, not me!
 
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