Combustion gases enter a gas turbine at 627 °C and 1.2 MPa at a rate of 2.5 kg/s and leave at 527°C and 500 kPa. It is estimated that heat is lost from the turbine at a rate of 20 kW. Using air properties for the combustion gases and assuming the surroundings to be at 25 °C and 100 kPa, determine the a) actual and reversible power outputs of the turbine, and b) exergy destroyed within the turbine.