Air enters an electrical furnace at 20oC, 100 kPa, with a volumetric flow rate of 30 m3/min. The furnace delivers air at 40oC to a duct system with three branches consisting of two 15-cm-diameter ducts and a 30-cm-diameter duct. The air behaves as an ideal gas, and the pressure in the exit ducts is 100kPa. If the velocity in each 15-cm duct is 4 m/s, determine, for steady operation: a) The mass flow of air entering the furnace, in kg/s. b) The volumetric flow rate in each 15-cm duct, in m3/min. c) The velocity in the 30-cm duct, in m/s.