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Spinning ring

  1. Jun 30, 2015 #1
    Hello all-

    This is a logistics question asking for some guidance, rather than one requiring scientific explanation.

    I'm currently in a battle of sorts with a friend to record the longest spinning ring possible (like a wedding ring). Basically, spin the ring on a table and time it until it completely stops. I'm curious about what factors would make the ring spin longer assuming the technique remains equal.

    I assume a heavier ring is better than a light one, a surface that has as low a coefficient of friction as possible (glass?) is best, and the ring should be rounded on it's side versus flat to limit surface area...

    Any other advice? As the ring slows there can be a significant amount of "wobble time" as it settles, this changes according to the shape but not sure what design is actually ideal. Also what about spraying the (glass) surface with a Teflon spray to reduce friction further? Or would that just make it slightly bumpy and slow it?

    Thanks for any help with this, I'll credit the forum when I break the current world record (which by the way is unofficially 3 minutes and eleven seconds, as far as I can find).
    S
     
  2. jcsd
  3. Jun 30, 2015 #2
    Also, the width and the diameter of the ring? How would those factor into spinning and wobbling time?

    Thanks!!
     
  4. Jun 30, 2015 #3
    You can distort the ring into the shape of a spherical bead with a small hole in it. This should give you a good spin time. Topologically, it's still a ring.
     
  5. Jun 30, 2015 #4
    Well it has to be a legitimate wearable ring, but I appreciate how that could help, thanks.
     
  6. Jun 30, 2015 #5
    Oh, that kind of ring!

    A smooth wedding ring would work best. It's made of gold alloy, so it's dense. 24 carot might work better. The cross section does a good job in minimizing air drag; it's close to the elliptical cross section used in biplane bracing wires. The greater the mass, the longer it should spin. Do you have a size 10 finger?
     
  7. Jun 30, 2015 #6
    A spinning ring of the sort a person wears on a finger will always generate heat even with very effective lubrication.
    I don't think it would be a hit as a fashion statement.
     
  8. Jul 13, 2015 #7
    Mission accomplished.
     
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