Air at a stagnation pressure 700kPa flows isentropic ally through a convergent-divergent nozzle. The design pressure at the nozzle exit is 56 kPa. If the back pressure is raised gradually, thereby creating a shock in the divergent portion of the nozzle, calculate:

a) the back pressure to locate the shock at the exit plane.

b) the minimum back pressure so that the flow in the nozzle is totally subsonic

c) if the back pressure is raised to 400kPa, find the area ratio of the shock, Mx, My, and M-exit.