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Homework Help: Power of a Pump draining a flooded basement

  1. Mar 29, 2008 #1
    1. The problem statement, all variables and given/known data

    Water is pumped steadily out of a flooded basement at a speed of 5.7m/s, through a uniform hose of radius 1.01cm. The hose passes through a window 2.96m above the waterline. What is the power (in W) delivered by the pump?


    2. Relevant equations

    Continuity and Bernoulli principles

    3. The attempt at a solution

    By using the radius, the cross sectional area is found to be 3.2047 * 10^-4 m^2.
    Multiply this by the velocity to find the flow rate I got: .001827 m^3/s or 1.827 kg/s.
    Multiply this by gravity (9.8 m/s^2) and the height (2.96m), I got 52.99 Watts.

    I don't know where I made a mistake, please help!
     
  2. jcsd
  3. Mar 30, 2008 #2

    mgb_phys

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    Science Advisor
    Homework Helper

    Your method is right but I get 54.07 ( how many figures did you carry through the calcs?)
     
  4. Mar 30, 2008 #3
    I tried 54.07 W but it's not correct either.
     
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