Two kilograms of air within a piston-cylinder assembly execute a Carnot power cycle with maximum and minimum temperatures of 810 K and 300 K, respectively. The heat transfer to the air during the isothermal expansion is 68 kJ. At the end of the isothermal expansion, the pressure is 650 kPa. Assuming the ideal gas model for the air, determine:

a. The thermal efficiency.
b. The pressure and the volume at the beginning of the isothermal expansion, in kPa and m^3 respectively.
c. The work and heat transfer for each of the four processes in kJ.
d. Sketch the cycle on a p-V coordinates.