Work done holding a weight?

  1. if a man is lifting weight while standing at rest, is he doing work microscopically?
     
  2. jcsd
  3. Doc Al

    Staff: Mentor

    If he's lifting it microscopically. :smile:

    Do you mean holding a weight without moving it? Or lifting a weight while standing in one place?
     
  4. Hootenanny

    Hootenanny 9,677
    Staff Emeritus
    Science Advisor
    Gold Member

    I think we have been through this discussion before, the physics definition of work is fundementally different to the physiological defintion of work. I'll try and dig out a link to the other thread.
     
  5. I mean, do his muscles perform any work as he is standing while lifting the weight at rest?
     
  6. Doc Al

    Staff: Mentor

    I will assume you mean that the man is holding a weight without moving it. In that case while there is no mechanical work done on the weight, there is certainly work going on in your muscles (they continually tense and relax)--that's why you get tired just holding a weight, even though you are not moving it. That internal work requires energy.
     
  7. Doc Al

    Staff: Mentor

  8. Hootenanny

    Hootenanny 9,677
    Staff Emeritus
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    Gold Member

  9. Doc Al

    Staff: Mentor

    Yes, way too slow to be useful. But the thread wasn't that old, so I found it in the list.
     
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