38. A piston-cylinder assembly contains 50 g of air holding a 50 kg piston against the stops at the top of the cylinder. The piston is a disk with a radius of 5.57 centimeters. The air, initially at 3 bar, 700 K, is slowly cooled until the piston just begins to move downward in the cylinder. The air behaves as an ideal gas, g = 9.8 m/s, and friction is negligible. The atmosphere outside the piston cylinder assembly is I bar. Sketch the process of the air on a p-V diagram labeled with the temperature and pressure at the end states. Also determine the heat transfer, in kJ, between the air and its surrounding