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Homework Help: Pulley with Multiple Weights

  1. Jun 15, 2013 #1
    1. The problem statement, all variables and given/known data
    The system is in equilibrium and the pulleys are weightless and frictionless. The weights are 25 N, 4 N, 4 N, and 1 N. Find the tension T. The acceleration of gravity is 9.8 m/s^2. Answer in units of N

    2. Relevant equations

    3. The attempt at a solution
    Honestly, we've never done with a pulley system with multiple weights in class, so I don't know how to begin. I also don't know how to address the fact that some pulleys are connected to the center of another pulley.

    Attached Files:

  2. jcsd
  3. Jun 16, 2013 #2
    You need to consider each pulley and each mass in a FBD. It is not difficult, but may be a bit tedious.
  4. Jun 16, 2013 #3
    Okay, but what do I do in a FBD for the 25N weight, which is connected to the center of a pulley?
  5. Jun 16, 2013 #4
    To make the problem easier first try to find the Tension in the 3 strings. And then as Voko said draw FBD of each mass. I don't think you need to make FBD of pulleys.
  6. Jun 16, 2013 #5
    The 25N weight has three forces: its own weight, the tension of the rope at the bottom, and the tension of the rope at the top. Just like any other weight, really.
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