$236$

$4\mathrm{.}7.$ Compute the motor size required to pump $28\mathrm{.}3cms(1,000cfs)$ through a $3,050m(10,000ft)$ long, $3\mathrm{.}66-m(12\mathrm{.}0-ft$ diameter pipeline to an upper reservoir $610m(2,000ft)$ above the lower reservoir. Use a friction factor of $0\mathrm{.}02$ and a pump efficiency of $80$per cent. Compute the energy input to the motor, if the motor efficiency is $90$ percent. Neglect minor losses.