This is not homework, but something work-related. However, I will post it here since it's homework-relatable. 1. The problem statement, all variables and given/known data Known variables: Qin , A (and obviously the diameter D of the pipe as well as g = 9.81 m/s2). The pipe outlet and the top of the tank is at atmospheric pressure. I want h1 to be as small as possible. What I'm looking for is an expression for h2. For the moment I'm assuming zero pipe friction. 2. Relevant equations Torricelli's law (v is the same as U): Q = U*A Might be more? 3. The attempt at a solution In steady state, Qin and Qout are equal (=Q) I tried solving for h using the two equations above and got h = Q2 / (2*g*A2) Is this h h1, h2, the sum of h1 and h2 or neither of these things? Is this even the right way to approach this problem?