Repeat Prob. 9–19 using helium as the working fluid.

Data From Repeat Prob. 9–19:

An air-standard Carnot cycle is executed in a closed system between the temperature limits of 350 and 1200 K. The pressures before and after the isothermal compression are 150 and 300 kPa, respectively. If the net work output per cycle is 0.5 kJ, determine 

(a) The maximum pressure in the cycle, 

(b) The heat transfer to air, 

(c) The mass of air. Assume variable specific heats for air.