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Potential energy of a shoelace

  1. Apr 27, 2007 #1
    How much potential energy is stored in a tied shoelace?
  2. jcsd
  3. Apr 27, 2007 #2


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    Gold Member

    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?
  4. Apr 28, 2007 #3
    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.
  5. Apr 28, 2007 #4
    No. the two works are unrelated.
  6. Apr 28, 2007 #5
    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.
  7. Apr 28, 2007 #6
    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.
  8. Apr 29, 2007 #7
    are you including energy stored as mass?
  9. Apr 29, 2007 #8
    I don't know whe you are asking. Anyway, not me!
  10. Apr 29, 2007 #9


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    Staff: Mentor

    We're done here.
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