4. The velocity ratio of a differential wheel and axle with D as the diameter of effort wheel and d1,and d2 as the diameters of larger and smaller axles respectively, is
8. The discharge over a rectangular weir, considering the velocity of approach, is (where H1 = Total height of water above the weir = H + HaH = Height of water, over the crest of the weir, and Ha = Height of water, due to velocity of approach)