5 A large tank is partly filled with water, the air space above being under pressure. A 2" hose connected to the tank discharges on the roof of a building 50 ft above the level in the tank. The friction loss is 18 ft. What air pressure must be maintained in the tank to deliver 0.436 cfs on the roof? Ans. 32.1 psi 200-mm diameter ( 300-mm diameter - 10.5 m/s P=1.21 kg/m - 3.2 m/s M=? =?