Air with a volumetric flow rate of 15,000 ft3/min enters an air-handling unit at 35oF, 1 atm. The air-handling unit delivers air at 80oF, 1 atm to a duct system with three branches consisting of two 26-inch-diameter ducts and one 50-inch duct. The velocity in each 26-inch duct is 10 ft/s. Assuming ideal gas behavior for the air, determine at steady state (a) The mass flow rate of air entering the air-handling unit (in lbm/s) (b) The volumetric flow rate in each 26-inch duct (in ft3/min) (c) The velocity in the 50-inch duct (in ft/s)