The speed of the wing is what causes the air to move around the two faces of the wing. The air has to move around the wing as it is being pulled through it. Im

The speed of the wing is what causes the air to move around the two faces of the wing. The air has to move around the wing as it is being pulled through it. Imagine pulling a fixed walled tube though the air, the air will move through the tube at roughly the speed that the tube is pulled through the air. Now imagine pulling a funnel that starts off large and gets smaller. The same air will now have to move faster to get through the funnel (higher pressure at the mouth of the funnel, lower at the end).