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Complex pulley for a boat

  1. Jul 12, 2010 #1
    A guy at work gave me this drawing I have attached and asked me to find the pulley ratio. Do I need any other information such as rope lengths, pulley diameters, or load? I traded in my machine design book and don't remember exactly how to calculate the ratio. Is there anything else I can calculate involving the load that would be helpful if I knew the weight of the boat. Thanks for any info.
     

    Attached Files:

  2. jcsd
  3. Jul 12, 2010 #2

    russ_watters

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    Staff: Mentor

    Nope, you don't need anything other than what is in the picture.
     
  4. Jul 13, 2010 #3
    So what I do is break up the pulley into sections and add up the tensions (T) right? With the tensions from each section I can get the ratio? Is this correct? I re-drew the drawing with my work on it. 9T:1T is my answer I just need someone to check that.
     

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  5. Jul 19, 2010 #4
    Can anyone confirm my answer or is it off?
     
  6. Jul 19, 2010 #5

    Q_Goest

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    Check to verify the sum of the forces is equal to zero in both the X and Y directions. Also verify the tension in any given rope is constant. If both of these are good, then the system is in static equilibrium.
     
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