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Homework Help: Pressure (Net Force)

  1. Aug 2, 2008 #1
    Water stands at depth 'd' behind a dam of width 'w'.

    Find an expression for the net force of the water on the dam.

    Evaluate the net force on a 100m high dam with a 60m water depth.

    For the first part:


    Then integrate from 0 to d which gives .5pw(d^2).
    Does this even look remotely correct, i have a feeling there should be a g somewhere in there?

    As for the 2nd part I'm stumped, how do I find the p term from that information.

    Any help as always is greatly appreciated :)
  2. jcsd
  3. Aug 2, 2008 #2

    Doc Al

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    Staff: Mentor

    How does pressure in a liquid depend upon depth?
  4. Aug 2, 2008 #3
    Weight of the water above it?
  5. Aug 2, 2008 #4

    Doc Al

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    Staff: Mentor

    Give a precise formula for pressure as a function of distance below the surface. (Look it up!)
  6. Aug 2, 2008 #5
    P = Po + pdg

    p = density

    But how do i relate that to what I'm doing >.<
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