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Efficiency of muscles

  1. Oct 22, 2008 #1


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    1. Efficiency is defined as work-out/work-in. Muscles operate with an efficiency of about 20% in converting energy internally into work externally. Accordingly, how much energy will be expended by a 60 kg person in the process of ascending several flights of stairs to a height of 25 m?

    2. I was using Wg=mgh

    3. I used the formula to get an answer of 14715 J, but I'm not sure where to go from here.
  2. jcsd
  3. Oct 22, 2008 #2
    Re: Efficiency

    Eg yes does equal mgh

    Now rmbr efficiency is work out (the amount of energy you get) / work in (how much work you actually put in)

    Now we know efficiency is 20 percent and what is the work you get out (hint)
  4. Oct 22, 2008 #3


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    Re: Efficiency

    Got it. Thanks.
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