Lift on an Airplane. Air streams horizontally past a small airplane's wings such that the speed is 70.0 m/s over the top surface and 50.0 m/s past the bottom surface. If the plane has a wing area of 16.6 m2 on the top and on the bottom, what is the net vertical force that the air exerts on the airplane? The density of the air is 1.20 kg/m3.