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Force on a lifted object

  1. Nov 28, 2009 #1
    Is the force done on a lifted object equal the weight of the object in newtons times the height lifted?
    F=mgh?
    I would have used this but I noticed it was the same equation for gravitational potential energy (or just potential energy)...So I thought I would ask you all after failing to find it online.
     
  2. jcsd
  3. Nov 28, 2009 #2

    Doc Al

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    Staff: Mentor

    I suspect you meant work instead of force.
    Yes, the work you must do to lift an object equals the increase in gravitational potential energy.
     
  4. Nov 28, 2009 #3
    no, no I was talking about force. I am trying to find the change in gravitational potential energy from a 2.0 object being lifted 3.5 meters.
    So I thought I would find Ke at the bottom.


    [tex]\sum w=\Delta ke[/tex]

    W=F.d

    So I want to know if F=mgh
    :)

    If I am completely full of crap and doing it wrong please tell me o_O
     
  5. Nov 28, 2009 #4

    Doc Al

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    Staff: Mentor

    No, F = mg (the weight). (Assuming you are doing the minimum work to overcome gravity.)

    So W = Fd = mgh.
     
  6. Nov 28, 2009 #5
    oh, duh xD I feel stupid now. thank you.
     
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