Consider a Mach 3 flow at 1 atm pressure initially moving over a flat horizontal surface. The flow then encounters a 20 degree expansion corner, followed by a 20 degree compression corner that turns the flow back to the horizontal. Calculate the pressure of the flow downstream of the compression corner. Note: You will find that the pressure downstream of the compression corner is different from the pressure upstream of the expansion corner, even though the upstream and downstream flows are in the same direction, namely horizontal. Why