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A Pulley System containing two double pulleys having a mechanical advantage of 6?

  1. Mar 30, 2004 #1
    How is this possible? Someone tell me please.
  2. jcsd
  3. Mar 30, 2004 #2
    2 single pulleys means 3 lengths of rope (one side to first pulley, first pulley to second pulley, second pulley to second side), hence a mechanical advantage of 3.

    2 double pulleys has twice the number of lengths of ropes, so we have 6 lengths of rope, and therefore a mechanical advangtage of 6.

  4. Mar 31, 2004 #3


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    Staff: Mentor

    A single pulley by itself may or may not provide a mechanical advantage. My advice o you, clz2 - draw it.
  5. Mar 31, 2004 #4
    Can you draw out your description? I am having trouble following the wording. I thought I understood what you said, but when I try to sketch it myself, I am a bit confused. I think that one side of the rope is attaching to the center of pulley one.
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