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Homework Help: Fluid statistics

  1. Apr 11, 2010 #1
    1. The problem statement, all variables and given/known data
    A u-shaped tube open to air at both ends contains some mercury. A quantity of water is carefully poured into the left arm of the tube until the vertical height of water is 15 cm.


    2. Relevant equations
    (a)What is the gauge pressure at the water-mercury interface?[ans 1.47*10^3Pa]

    (b)calculate the vertical distance h from the top of the mercury in the right-hand arm of the tube to the top of the water in the left-arm.[ans 13.9 cm]


    3. The attempt at a solution
    (a) p=p_0 +rho*g*h
    p = 0 + 13.6*10^3 *9.8*0.15
    p= 1.99*10^4
    (b) 13-1.47=13.5
     
    Last edited: Apr 11, 2010
  2. jcsd
  3. Apr 11, 2010 #2

    Doc Al

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    Staff: Mentor

    Check your value for the density of water.
     
  4. Apr 11, 2010 #3
    The answers are already given in brackets so my problem is deriving them:confused:
     
  5. Apr 11, 2010 #4

    Doc Al

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    Staff: Mentor

    You gave an attempted solution and I stated why it was wrong. Did you look up the density of water?
     
  6. Apr 11, 2010 #5
    Thanks a million realy appreaciate:smile:
     
  7. Apr 11, 2010 #6
    How do i then tickle (b) im totally clueless on that
     
  8. Apr 11, 2010 #7

    Doc Al

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    Staff: Mentor

    Draw a picture. Hint: At the same vertical position (height), the pressure must be the same. Imagine a horizontal line that intersects the mercury/water boundary.
     
  9. Apr 12, 2010 #8
    Thank you very much Pf mentor i got the solution to the question:smile::smile:
     
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