Five kg of carbon dioxide (co2) gas undergoes a process in a well-insulated piston-cylinder assembly from 2 bar 280 k to 20 bar, 520 k. if the carbon dioxide behaves as an ideal gas, determine the amount of entropy produced, in kj/k, assuming (a) constant specific heats with cp=0.939 kj/kg. k (b) variable specific heats. compare the results of parts (a) and (b)