A gas-turbine power plant operates on the simple Brayton cycle between pressure limits of 100 and 1600 kPa. The working fluid is air, which enters the compressor at 40⁰C at a rate of 850 m3 /min and leaves the turbine at 650⁰C. Using variable specific heats for air and assuming a compressor isentropic efficiency of 85 percent and a turbine isentropic efficiency is 880 percent, determine (a) the net power output, (b) the back work ratio and (c) the thermal efficiency.