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Muscle/Energy question

  1. Feb 25, 2008 #1
    1. The problem statement, all variables and given/known data
    This isn't homework, just something I'm wondering.
    Using the theories and links between Work and Energy, why is a larger muscle able to lift more (and/or find it easier to lift the same mass) than a smaller one?

    2. Relevant equations
    W = Fd
    W = E_f - E_0
    KE = (1/2)mv^2
    PE = mgh
  2. jcsd
  3. Feb 25, 2008 #2


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    Science Advisor

    A larger muscle can apply more force and so, since, W= fd, do more work. It takes exactly the same force and energy to lift a given object, whether the muscle is larger or not. It is just that the stronger (larger) muscle can apply more force. That's pretty much what "stronger" means!

    It is also true that a longer arm might have more mechanical advantage and so be able to lift an object while applying less force (but using the same energy) but that is a matter of bone length, not muscle size or strength.
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