1. Not finding help here? Sign up for a free 30min tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Help please -- Problem of hydrostatics force in flat surfaces

  1. Mar 26, 2015 #1
    1. The problem statement, all variables and given/known data

    upload_2015-3-26_14-17-21.png
    2. Relevant equations


    3. The attempt at a solution
    I could know the pressure in point B

    upload_2015-3-26_14-18-23.png

    If I calculate the heigh of pressure I got: upload_2015-3-26_14-19-0.png


    But I don't know where is my free surface in the container 3, is it down??

    I don't know how to keep doing it.....
     
  2. jcsd
  3. Mar 26, 2015 #2

    haruspex

    User Avatar
    Science Advisor
    Homework Helper
    Gold Member
    2016 Award

    On the face of it, you need to integrate over the sloping surfaces to get the vertical force (because the pressure varies with depth).
    Let me suggest a simpler approach.
    Consider an object of known volume sitting at the bottom of a tank of fluid of known density and depth. The shape is arbitrary, except that the base is flat and sits squarely on the flat bottom of the tank. The contact surfaces are not perfectly smooth, though, so fluid can readily seep under the object.
    What is the net upward force on the object from the fluid?
    What is the upward force on the object arising only from the fluid that seeps under the object?
    What can you conclude about the downward force on the object only arising from the fluid elsewhere?

    Can you see how this would help you figure out the force contribution from each compartment in your problem?
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted