# Determine the maximum height a pump can suck up water

I am working on a homework problem that presents the scenario of trying to raise water from a small reservoir of depth 8 m whose surface is 25 m below a pump that can maintain a pressure differential of 10 atm. According to the problem this is not possible, but I am charged with 1) finding the maximum height that this water could be sucked up, and 2) finding an optimal placement for the pump (instead of at the top of the hill) so that it could suck the water up. I am not given how much water is in the reservoir. I do not know where to begin. I do not really understand how the pump works (the instructor has said it does not really matter, all you need to know is that it is a "black box" that maintains this pressure differential). I would appreciate some guidance on where to begin or how to set up my equations.

-
Answers here should focus on the conceptual matter and not on the particulars of this problem in order to remain consistent with the FAQ. –  dmckee Nov 3 '12 at 22:49
@dmckee, I did not request the answer to the question, but just how to think about this. Because of my lack of intuition (and knowledge) in these things I cannot do anything with the fact that there is a 10 atm pressure differential, I do not know what that really means in terms of generating a suction force upwards from a certain height. –  tacos_tacos_tacos Nov 3 '12 at 23:43
Yes, and we appreciate it. That was a reminder for our regulars who can get excited. –  dmckee Nov 4 '12 at 2:41
@dmckee I thought our standard practice was not to allow "I don't know where to begin" questions like this one. –  David Z Nov 4 '12 at 4:46