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Homework Help: Pulley with mass

  1. Nov 15, 2009 #1
    1. The problem statement, all variables and given/known data
    There is a object with mass m connected by a massless rope to a pulley with mass M and radius R. Find the angular acceleration of the pulley when the mass is let go.

    2. Relevant equations
    torque= I*angularacceleration(aa)=r*F

    3. The attempt at a solution

    pulleys with mass give me trouble all around.
    I know to find the angular acceleration i must find the tension of the the rope.
    Fnet= T= mg-Fpulley
    I do not know how to find the "force" of the pulley, or the torque. could anyone show me how to find the force of the tension.
  2. jcsd
  3. Nov 16, 2009 #2


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    Science Advisor
    Homework Helper

    Welcome to PF!

    Hi wiveykid! Welcome to PF! :smile:

    (try using the X2 tag just above the Reply box :wink:)
    Nope … try not to find internal forces you're not asked for! :wink:

    Hint: look for an equation of motion of the system as a whole. :smile:
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