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How can you find height in bernouli equation?

  1. Mar 21, 2012 #1
    I am having a hard time figuring out the step in the equation. For an example, I was given a problem that water flows from the bottom at a velocity of 5.0m/s up to a bucket at (unknown) height. The hose radius is the same so it is not given.

    Density p= 1000kg/m^3
    Gravity= 9.80m/s^2
    Radius of hose= any number but equal in all


    So I am trying to find the maximum height but...the only known informations were given. What is the step in finding v_2 and y_2?

    Please help! Thanks
  2. jcsd
  3. Mar 21, 2012 #2


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    Homework Helper

    Is this a trick question? If the hose radius never changes, then the velocity of the water never changes (ingoring tiny changes in density versus pressure, mass flow never changes, volume flow increases as density decreases). As long as a pump can supply sufficient pressure, there's no limit to height, unless the required pressure is so great (98,692 atm, 100,000 bar, 10 giga-pascals) that it turns water into ice. The pressure of the water will decrease with height, by ρ g h. Density (ρ) will decrease slightly as pressure decreases.
    Last edited: Mar 21, 2012
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