A centrifugal pump discharges 500 GPM through a 12-inch diameter impeller. The fluid leaves the impeller with a tangential velocity of 17 ft/sec. If water, @ 68°F, enters the impeller via radial flow (i.e. no whirl), and the inner radius and thickness of the impeller are 1.75 inches (assume a constant thickness of the impeller), and if the pump speed is 1775 rpm, with a head loss of 4.5 feet. What is the horsepower input to the flow by the pump?
a. 3/4 HP
b. 1.25 HP
c. 2.5 HP
d. 4.4 HP
e. 6 HP
(Based on the options above, what is the correct answer?)