Hydrogen at 15 bar, 450°c enters a turbine and expands to 2 bar, 160°c with a mass flow rate of 0.2 kg/s. the turbine operates at steady state with negligible heat transfer with its surroundings. assuming an ideal gas model, constant specific heats, with k = 1.37 and neglecting kinetic and potential energies, determine (a) the isentropic turbine efficiency (b) the exergetic turbine efficiency let t0 = 25 °f, p0 = 1 atm. round your answers to 3 significant digits.