Which of the following is NOT a part of an airfoil?

The correct answer is the gravitational pull because it is not a structural or functional component of an airfoil. An airfoil consists of various physical parts that contribute to its aerodynamic properties, namely the leading edge, upper camber, and trailing edge, all of which play crucial roles in generating lift and managing airflow over the surface of the airfoil.

The leading edge refers to the front part of the airfoil, where airflow first contacts the surface. This design is essential for controlling the smooth flow of air over the wings. The upper camber is the curvature of the upper surface of the airfoil, which helps generate lift as the air travels faster over this curved surface compared to the lower surface. The trailing edge, on the other hand, is the rear part of the airfoil and serves to manage the airflow separating from the wing, reducing drag and improving performance.

Gravitational pull is a universal force acting on all objects but does not represent a physical structure or functional aspect of an airfoil itself; rather, it affects how the airfoil interacts with other forces during flight. Thus, it is not considered a part of an airfoil.