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Homework Help: Incorrect calculator?

  1. Jun 20, 2006 #1
    I believe that this calculator generates answers assuming that the only force acting on a falling object after it has encountered a stopping surface is the force of the stopping surface. The calculator needs to factor in gravity throughout the whole fall. Would someone else please verify?
    Click Mechanics, work-energy principle, and then impact force of falling object, and "Since you know velocity, mass, and kinetic energy, can you predict the force of impact?"
    Example numbers:
    m=50kg, h=10m, d=5m
    stopping force should be about 1480N, but the calculator is saying 980N.
    Last edited: Jun 21, 2006
  2. jcsd
  3. Jun 20, 2006 #2


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    Read the little note at the bottom of that page.

    That should take care of your problem (you probably should use d=5, h=5 to describe the situation I think you have in mind). If not for this disclaimer, the calculation would be, as you point out, wrong for the general case where d is not necessarily small compared to h.
  4. Jun 20, 2006 #3
    I didn't take time to read that disclaimer carefully. Thanks for the quick answer!
  5. Jun 21, 2006 #4


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    Dearly Missed

    It is not a disclaimer, it is a caveat. :mad:
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