How to calculate potential energy of water in a tank?

  1. Suppose you have a cylindrical tank of water that is filled to height h. Total mass of water is M. How do you calculate the potential energy of water relative to the base of the tank?
     
  2. jcsd
  3. berkeman

    Staff: Mentor

    Welcome to the PF.

    What is the context of the question? What do you intend to use the PE for?
     
  4. I just want to know what the stored p.e. is
     
  5. berkeman

    Staff: Mentor

    How come? And how did the water get into the tank? And where is it going to go as it flows out of the tank?

    PE is relative to something, it is not an absolute quantity. It is valid to say that the stored PE of water in a tank is zero. And then if the water flows out to some other tank, there may be a change in the stored PE...
     
  6. does this make sense:
    g=gravitational acc
    y=water level from base
    A=area of water surface
    r=water density
    m=total mass of water
    U=PE

    then dU=grAydy
    U=1/2grAh^2=1/2mgh (m=rAh)
     
  7. Doc Al

    Staff: Mentor

    Yes, that's fine.
     
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