Recall from Chap. 8 that the exit velocity from a simple reservoir is \nu =\sqrt{2gh}, which is the same result that one obtains for the velocity of a mass particle that is dropped from a resting position at height h above the surface. If one wishes to determine the latter result (for the first time) experi-mentally given the general relation \nu =f(m,g,h) Control Volume and Semi-empirical Methods for a particle of mass m, and neglecting air resistance, one might seek to perform multiple experiments for different masses m and heights h. Let us see what Buckingham Pi would suggest, however.