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Please help, spinning chain question

  1. Oct 11, 2006 #1
    I need to find the tension of a spinning chain with mass per unit length u and angular speed w. I need to show that em waves on the chain travel at the same speed as the chains linear speed. please help if you can,
  2. jcsd
  3. Oct 11, 2006 #2
    forgot to mention its a loop of chain
  4. Oct 11, 2006 #3


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    Since it is a loop, I assume it is spinning about an axis perpendicular to the plane of the loop. Every bit of the chain of length dl has a mass dm that is accelerating toward the center of the loop. The net force on half of the loop is the integral of the required centripetal force over the semicircle. The result will be directed from the midpoint of the semicircle to the loop center. This force is supplied by the two ends of the opposite semicircle as the tension in the loop. I think this approach will get you there for finding the tension. I really don't get the part about the EM waves.
    Last edited: Oct 11, 2006
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