Two kilograms of air within a piston–cylinder assembly execute a carnot power cycle with maximum and minimum temperatures of 750 k and 300 k, respectively. the heat transfer to the air during the isothermal expansion is 60 kj. at the end of the isothermal expansion the volume is 0.4 m3. assuming the ideal gas model for the air, determine (a) the thermal efficiency. (b) the pressure and volume at the beginning of the isothermal expansion, in kpa and m3, respectively. (c) the work and heat transfer for each of the four processes, in kj. (d) sketch the cycle on p–v coordinates.