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Homework Help: Find mass of skaters

  1. Nov 16, 2011 #1
    1. The problem statement, all variables and given/known data
    Two identical ice skaters are holding onto opposite ends of a very long spring with a spring constant of 650 N/m. While spinning in a circle, the skaters frequency of revolution is measured to be 0.85 Hz. What is the mass of the skaters?


    2. Relevant equations
    F = kx


    3. The attempt at a solution
    F = (650 N/m)x ?
     
    Last edited: Nov 16, 2011
  2. jcsd
  3. Nov 17, 2011 #2

    ehild

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    Remember, circular motion is the resultant of two perpendicular SHM with the same frequency and amplitude and phase difference of pi/2.


    ehild
     
  4. Nov 17, 2011 #3
    Oh so then u use the equation
    f=(1/2∏)√(k/m)
    And the m needs to be 2m...ok got it!

    Thank you!!
     
  5. Nov 17, 2011 #4

    ehild

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    No, m is not twice that of one skater-just the opposite.

    Both skaters spin along the same circle. The situation is the same for each of them as if there was a pole at the centre, and half of the spring connected to the pole with one end and the other end to the skater. What is the spring constant of a halved spring?

    ehild
     
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