4-29 A piston-cylinder device contains 0.85 kg of refrigerant-134a at -10°C. The piston that is free to move has a mass of12 kg and a diameter of 25 cm. The

local atmospheric pres-sure is 88 kPa. Now, heat is transferred to refrigerant-134auntil the temperature is 15°C. Determine (a) the final pres-sure, (b) the change in the volume of the cylinder, and (c) the change in the enthalpy of the refrigerant-134a.