Q4. A thin plate (1.2m x1.2m) is standing parallel to an air flow of 3 m/s. Please calculate: (20 points) a) Friction factor of air acting on the plate, b) Friction force acting on both surfaces of the plate, c) Boundary layer thickness at the end of the plate d) Shear stress acting at the end of the plate. Data: vair =1.486x10-5 m/s, pair =1.382 kg/m?