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Homework Help: Fluid velocity (Bernoulli's Principle?)

  1. Apr 10, 2010 #1
    1. The problem statement, all variables and given/known data
    A wide tank contains a non-viscous liquid. The surface of the liquid is at a height 0.5 m above a hole situated at the bottom of the tank. Assuming streamline flow, calculate the velocity of the liquid emerging from the hole.

    2. Relevant equations
    P + 1/2 Dv^2 + Dgh = constant (?)

    3. The attempt at a solution
    h=0.5 m
    non-viscous -> density unchanged
    Then? I can't continue.
  2. jcsd
  3. Apr 11, 2010 #2
    Write out the constant side of Bernoulli's equation. It will describe the state of the water at the hole.

    Hint: Since the water coming out the hole is coming into air the pressure on the water will also be atmospheric pressure (so it cancels from both sides).
  4. Apr 11, 2010 #3
    "non-viscous -> density unchanged"

    Non-viscous means moving without frictional energy loss. When the densy is unchanged, it is incompressible. In this problem you assume incompressible as well as non viscous.
    Last edited: Apr 11, 2010
  5. Apr 11, 2010 #4
    Thanks AtticusFinch for your hints and Phrak for your correction (I just mixed them up). I think I've arrived at the answer.

    Is it correct?

    Attached Files:

  6. Apr 11, 2010 #5
    Yeah that looks correct to me. However you final units should be m/s
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