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Homework Help: Magnitude of Net Torque

  1. Apr 7, 2010 #1
    1. The problem statement, all variables and given/known data

    A one-piece cylinder has a core section protruding from the larger drum and is free to rotate around its central axis. A rope wrapped around the drum of radius 1.14 m exerts a force of 4.41 N to the right on the cylinder. A rope wrapped around the core of radius 0.54 m exerts a force of 8.94 N downward on the cylinder.

    What is the magnitude of the net torque acting on the cylinder about the rotation axis?
    Answer in units of N ยท m.
    2. Relevant equations

    Torque(net)=Torque 1-Toque 2
    Torque=rFsin(phi)

    3. The attempt at a solution
    I attempted to find the 2 Torques by multiplying the radius by the given forces. I then subtracted the negative force going clockwise (F1) from the positive force going counter clockwise.
     
  2. jcsd
  3. Apr 8, 2010 #2
    I have the same problem. The one I have is that r = 1.18m, F = 3.33 N for T1, I got -(3.33)(1.18) = -3.9294 (CW = negative). My T2 is (0.42)(6.7) = 2.814. And I do T1 + T2 = R2T2 - R1T1 = -1.1154. And I got it wrong. I also tried to square T1 and T2 since it says magnitude, but it doesn't work either. PLEASE HELP!
     
  4. Apr 11, 2010 #3
    I am still completely lost on this problem.
     
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