1. Limited time only! Sign up for a free 30min personal 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!

Horizontal force across a partition

  1. May 13, 2016 #1
    1. The problem statement, all variables and given/known data
    Find the horizontal force across the partition in a water tank with two compartments, one filled with water to x height and the other with water to y height. I've worked out the thrust acting on the partition as a result of density, height, gravity and average depth, so I have two horizontal vectors, with which to find the total horizontal force.

    2. Relevant equations
    F=PaA
    P=pgh
    F=pgha

    3. The attempt at a solution
    (sum) Fx=(Force from oil) - (Force from water). Problem is I don't know which force is in which direction relative to the partition. The only solution I can see, which would make sense is adding the two forces together. Is this correct?
     
  2. jcsd
  3. May 14, 2016 #2

    Simon Bridge

    User Avatar
    Science Advisor
    Homework Helper
    Gold Member
    2016 Award

    I'm confused.
    You write,
    ... but "oil" is not mentioned in the problem statement, which says:
    ... just water on each side of the partition.

    Looking at those heights:
    Lets say y>x, then what else is in the tank at height h: y-x<h<y? What about when h>y?

    ... but your problem statement says:
    ... which direction is "horizontal"?
     
  4. May 14, 2016 #3
    The question says there is a tank which has a vertical partition across the width. There are two compartments in the tank, one contains water the other oil. I have worked out the hydrostatic force each liquid exerts on the partition. Now I have to find the 'horizontal force on the partition', Do I add the two forces together?
     
  5. May 14, 2016 #4
    Horizontal parallel to the base of the tank, normal to the vertical partition, I assume.
     
  6. May 14, 2016 #5
    Does the horizontal resultant force equal the difference between the two opposing forces?
     
  7. May 15, 2016 #6

    Simon Bridge

    User Avatar
    Science Advisor
    Homework Helper
    Gold Member
    2016 Award

    The resultant force is the vector sum of all the forces ... the horizontal resultant force is the horizontal component of the resultant force.
    In your case - where do the forces come from? Where do the forces act?

    I am making some assumptions about what the question is really asking ... technically the net horizontal force on the partition must be zero since it is not accelerating. I am guessing the question wants the net force due to the difference in pressure on each side.
     
    Last edited: May 15, 2016
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted