$(2)$ A Brayton cycle with regenaration using air as the working fluid has a

pressure ratio of $8.$ The minimum d maximum temperatures in the cycle are

$310$ and $1350$ K $.$ Assuming an adiabatic efficiency of $75$ percent for the compressor

and $82$ percent for the turbine and an $65$ percent for the regenerator, determine

a$)$ the air temperature at the turbine exit

b$)$ the net work output

c$)$ the thermal efficiency. Assume variable specific heats for air.