6.6 During the test of a centrifugal pump, a Bourdon pres- sure gage just outside the casing of the 12-in.-diameter suction pipe reads -6 psig (i.e., vacuum). On the 10-in.-diameter discharge pipe another gage reads 40 psig. The discharge pipe is 5 ft above the suction pipe. The discharge of water through the pump is measured to be 4 ft /s. Compute the horsepower input of the test pump