Air, at a stagnation pressure of 7.20 MPa (abs) and a stagnation temperature of 1100 K, flows isentropically through a converging-diverging nozzle having a throat area of 0.01 m2. Determine the speed and the mass flow rate at the downstream section where the Mach number is 4.0. Explain your answer in explicit details, and list all steps leading up to your final answer.