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Force of water in a container

  1. Jun 15, 2006 #1
    Hello everyone, newbie here.. sorry if I posted this in the wrong place.

    We just went over fluids today. And I can’t seem to solve a problem that has to do with force due to pressure. The problem is: An open U shaped container is filled with water to the top. What is the force due to the water on side A?

    Now pressure = (density)*(gravity)*(height) I believe.
    Force is pressure*area. Since side A is a square, that’s simply length squared for area.

    So I believe the equation to use in this case is Force = (density)*(gravity)*(height)*(Area).

    But for some reason, I keep getting the wrong answer. Here’s a badly drawn picture of the container. Can anyone give me some pointers?

    http://img151.imageshack.us/img151/9338/untitled5vd.th.jpg [Broken]
    Last edited by a moderator: May 2, 2017
  2. jcsd
  3. Jun 15, 2006 #2

    Doc Al

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    Staff: Mentor

    Since it's an open container, don't forget to include the effect of atmospheric pressure. Otherwise, your thinking is correct (assuming you use the correct height).
  4. Jun 15, 2006 #3


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    Homework Helper

    Looks ok to me, Maybe you should check your units.
  5. Jun 15, 2006 #4
    Thank you for the help! Turns out it was atmospheric pressure. You have to add it to the pressure of the water and then multiply by area to get force.

    I should read more carefully. :)
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