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Homework Help: Bernoullis equation

  1. Aug 11, 2015 #1
    1. The problem statement, all variables and given/known data
    Was flicking through a textbook and decided to give a question a try.

    Flow through a converging diverging nozzle, determine pressure at throat picture attached.
    Pressure at inlet = 50cm head, 4905PA
    inlet dia = 2cm
    throat dia = 1 cm
    density of water = 1000kg/m^3

    2. Relevant equations
    Bernoullis equation

    3. The attempt at a solution
    Cant find pressure at throat as both velocities are unknown,
    Area of inlet = 3.142cm^2
    area of throat = 0.785 cm^2.
    We could make the outlet atmospheric, answer was around 7mH2o head.

    Attached Files:

  2. jcsd
  3. Aug 11, 2015 #2


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    Staff Emeritus
    Science Advisor
    Homework Helper

    This is generally not a good idea, unless you have studied all the material covered up to that point thoroughly.

    What you also need here, to find the inlet velocity, is known as Torricelli's Law:


    That's why you must study the figures included with the problem.
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