4- A thin airfoil can be approximated as a flat plate. The airfoil is set at an angle of 10 to an airflow with a Mach number of 2, a temperature of -50 C, and a pressure of 50 kPa. Using linearized theory, find the pressures on the upper and lower surfaces of this wing. 5- An airfoil has a triangular cross-sectional shape. The lower surface of the airfoil is flat and the ratio of the maximum thickness to the chord is 0.1. The maximum thickness occurs at a distance of 0.3 times the chord downstream of the leading edge. If this airfoil is placed with its lower surface at an angle of attack of 2 to an airflow in which the Mach number is 3, use linearized theory to determine the distribution of the pressure coefficient over the surface of the airfoil. M = 3 c/3 0.1c 2c /3