4. (10 marks total) Two steady flows of air enter an adiabatic mixing chamber at low velocity. At point 1 a mass flow m₁ = 5 kg/s enters at P₁ = 200 kPa, T₁ = 100°C, while at point 2 a volume flow V = 3 m³/s enters at T₂ = 20° with the same pressure (P2 = P₁). The flow leaving 2 the mixing chamber enters an adiabatic reversible nozzle and is expanded to P4 = 120 kPa. You may assume that air is an ideal gas with constant specific heats. (a) (3 marks) Determine the mass flow rate and nozzle mixing chamber 3 temperature of the air at the mixing chamber outlet. State any assumptions you may need. (b) (5 marks) Find the nozzle exit temperature and flow velocity. (c) (2 marks) Determine the cross-sectional area of the nozzle exit.