Combustion gas flows into the turbine of an industrial gas turbine engine at 1240°c, 1.5 mpa, and 310 m/s. it exits the turbine at 670°c, 80 kpa, and 170 m/s. the outlet is 1.35 m below the inlet. the mechanical power output of the turbine is 18 mw. heat is lost through the turbine casing to the surroundings at a rate of 0.35 mw. all properties of the gas are approximately equal to properties of air. prove that fluid flowing into a control volume does work on the contents of the control] (a) volume at a rate of pv per unit mass. determine the mass flow rate of gas through the turbine (state any assumptions clearly) (b) determine the percentage contributions of enthalpy, kinetic energy, and gravitational] (c) potential energy to the turbine's mechanical power. (d) determine the isentropic efficiency of the turbine.