Air expands through a turbine operating at steady state on a test stand. At the inlet, p=50 psia, T=1500 degrees R, and at the exit , p=14.5 psi. The volume flow rate of air entering the turbine is 2000 ft^3/min, and the power developed is measured at 2000 horsepower. Assuming that the turbine is adiabatic, determine the exit temperature.