A cycle using helium in a piston-cylinder device starts at T1 = 300 K and P1 = 0.2 MPa. The helium is then compressed isothermally until V2 = V1/10. Heat addition at constant volume then raises the temperature to T3 = 1500 K. An isothermal expansion followed by a constant-volume cooling returns the helium to the initial state 1. Assume that all processes are carried out slowly sp that equilibrium is always maintained. (T) Sketch (to scale) this cycle on a P-v diagram. Choosing the helium to be your system, determine the work and heat transfer (kJ/kg) for each process in the cycle. Determine the thermal (first-law) efficiency of this cycle. step 1: W1 = -1435 kJ/kg; step 2: q2 = 3738 kJ/kg; step 3: w3 = 7173 kJ/kg; step 4: 4 = -3738 kJ/kg; = 0.526