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Pulleys and forces

  1. Apr 5, 2008 #1
    1. The problem statement, all variables and given/known data
    An object of mass 12.5 kg hangs from very light pulleys as shown here:
    What force must be applied to the rope so that the mass stays at rest?

    2. Relevant equations
    Fnet = ma.....

    3. The attempt at a solution
    I am really clueless when it comes to this question. I know the net force must be 0 because there is no acceleration occuring b/c it must be at rest. Please help.
  2. jcsd
  3. Apr 5, 2008 #2
    You are correct by saying that the net force must be 0, since the system will be in static equilibrium.
    Try drawing a free body diagram for each pulley.
    If you correctly label the tensions in the strings and sum up the forces in both the x and y directions, the problem will become much easier.
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