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Homework Help: 2 masses on a pulley

  1. Apr 8, 2010 #1
    1. The problem statement, all variables and given/known data
    A mass [tex]m_{1}[/tex] is hanging from a light cord which is strung over a pulley of moment of inertia, I, and radius [tex]R_{0}[/tex] and connected to a mass [tex]m_{2}[/tex] which is sliding on a rough horizontal surface with coefficient of friction [tex]\mu_{k}[/tex].

    a) What is the acceleration of the system?
    b) What are the tensions in each part of the cord?

    All help is appreciated! :)


    2. Relevant equations
    [tex]\Sigma[/tex]F = ma
    [tex]\Sigma\tau[/tex] = m[tex]R^{2}\alpha[/tex]

    3. The attempt at a solution
    I started by trying to sum up all the forces and torques but I don't know where to go from there.

    [tex]\Sigma F_{x} = T - \mu m_{1}g = (\mu m_{1} + m_{2})g = ma[/tex]
    [tex]\Sigma F_{y} = T = m_{2}g[/tex]
    [tex]\Sigma \tau = rF_{x} + rF_{y}[/tex]
    1. The problem statement, all variables and given/known data

    2. Relevant equations

    3. The attempt at a solution
  2. jcsd
  3. Apr 8, 2010 #2


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    Homework Helper

    Always start by drawing a free-body diagram on each object, including the pulley, and writing out Newton's second law for each object.
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