$3\mathrm{.}4.$ An $8-$in$.$ suction by $6-$in$.$ discharge pump is being tested in the

laboratory. The head rise across the pump is measured with a

water$/$mercury differential manometer. At a flow rate of $3cfs,$ the manometer reads $215-cm$ differential. $($a$)$ Calculate the total dynamic

head $($TDH$).($b$)$ What would happen to the TDH if friction losses

were included in the calculation? $($c$)$ What is the water horsepower?