A machine operating with the Carnot cycle, using as working fluid a mole of ideal gas whose Cv=25 J/(mol*K) and operating from 5 atm and 350C, undergoes an isothermal expansion up to a pressure of 3 atm to continue with an expansion until the temperature drops to 50 C. Calculate the net heat of the cycle in KJ, the net work of the cycle in KJ, the net internal energy change of the system KJ and the efficiency of the process in percent.