A 200-ft3/min-flow of air at 14.7 psia and 60 F enters a fan with negligible inlet velocity. The fan discharge duel has a cross-sectional area of 3 ft2. The process across the fan is isentropic (reversible and adiabatic). The fan discharge pressure is 14.8 psia. Determine (a) the velocity in the discharge duct (ft/min) and (b) The size of motor requited to drive the fan (hp).