How does an airfoil generate lift?

The generation of lift by an airfoil is a complex interaction involving both Bernoulli's principle and Newton's laws of motion. According to Bernoulli's principle, as the speed of air over the upper surface of the airfoil increases, the pressure decreases. This difference in pressure creates an upward force, known as lift.

Simultaneously, Newton's third law states that for every action, there is an equal and opposite reaction. As the airfoil moves through the air, it deflects air downwards, generating a reaction that pushes the wing upwards. This dual approach—combining the effects of differing air pressures due to speed and the change in momentum of the air—provides a comprehensive understanding of lift generation.

The other options do not fully encapsulate the mechanisms at play. Creating a vacuum above the wing describes a part of the Bernoulli effect but simplifies the process too much. High speeds are necessary for lift, but they don’t explain how lift is created on their own without considering air pressure differences. Likewise, manipulating air pressure alone does not account for the need for airfoil shape or the geometry of motion that contributes to lift generation.