Air is contained in a cylinder fitted with a frictionless piston. Initially the cylinder contains 0.5 m of air at 1.5 bar, 20C. The air is then compressed reversibly according to the law pv" = constant until the final pressure is 6 bar, at which point the temperature is 120C. Determine: (a) the polytropic index n, (b) the final volume of air, (c) the work done on the air and the heat transfer, and (d) the net change in entropy.