Pl.17 The Hazen-Williams hydraulics formula for volume rate of flow Q through a pipe of diameter D and length L is given by where Ap is the pressure drop required

to drive the flow.What are the dimensions of the constant 61.9? Can this formula be used with confidence for various liquids and gases? Q \approx 61.9 D^{2.63}\left(\frac{\Delta p}{L}\right)^{0.54}