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Homework Help: Momentum problem

  1. Oct 30, 2004 #1
    A 3kg puck revolves in a circle on a frictionless table at the end of a 50cm long string. The puck's angular momentum is 3kg (m^2/s). What is the tension in the string?

    Need help in starting this problem
     
  2. jcsd
  3. Oct 30, 2004 #2
    Knowing the angular momentum what can you find? How does this relate to force or tension?
     
  4. Oct 30, 2004 #3
    L= mrv
    therefore
    3kg*.25m*v = 3kgm^2/2
    v=4m/s
    F=(mv^2)/r
    (3kg*16m/s)/(.25m) = 192N

    is this right?
     
    Last edited: Oct 31, 2004
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