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Homework Help: Torque On Disk

  1. Mar 12, 2012 #1
    1. The problem statement, all variables and given/known data

    A uniform disk with mass m = 9.32 kg and radius R = 1.37 m lies in the x-y plane and centered at the origin. Three forces act in the +y-direction on the disk: 1) a force 340 N at the edge of the disk on the +x-axis, 2) a force 340 N at the edge of the disk on the –y-axis, and 3) a force 340 N acts at the edge of the disk at an angle θ = 30° above the –x-axis.

    Q: If the disk starts from rest, what is the rotational energy of the disk after the forces have been applied for t = 1.5 s?

    2. Relevant equations


    3. The attempt at a solution
    I just want to check whether my working is correct or not.

    I use ω=ωi+alpha*t which ωi is zero,then i sub in the values to E=1/2*I*ω^2 to find the rotational energy.
    Please help me check my workings is it right?
    Thank you.
  2. jcsd
  3. Mar 12, 2012 #2


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    hi ctwokay! :smile:

    (have an alpha: α and try using the X2 and X2 buttons just above the Reply box :wink:)
    yes, that's fine! :smile:
  4. Mar 12, 2012 #3
    thank you very much
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