Nitrogen enters a nozzle operating at steady state at 0.2 MPa, 550 K with a velocity of 1 m/s and undergoes a polytropic expansion with n = 1.3 to 0.15 MPa. Using the ideal gas model with specific heat ratio, k = 1.4, and ignoring potential energy effects, determine (a) the exit velocity, in m/s, and (b) the rate of heat transfer, in kJ per kg of gas flowing through the nozzle.