A gas-turbine power plant operates on the simple brayton cycle between the pressure limits 100 and 2000kPa. The working fluid is air, which enters the compressor at 40 Celsius at a rate of 700 m^3/min and leaves the turbine at 650 Celsius. Using variable specific heats for air and assuming the compressor isentropic efficiency of 85 percent and turbine efficiency of 88 percent, determine a) the net power output, b) the back work ratio, and c) the thermal efficiency. Assume the temperature at state 3 is 1421 Celsius.