Drag is defined as:

Drag is defined as:

• A. The resistance caused by air or water moving over a surface
• B. The gravitational force on a body
• C. The energy cost of movement
• D. The initial velocity of projection

Answer: (A)

When an object moves through air or water, the fluid pushes back against that motion. This opposing force is called drag. It’s the resistance the surface experiences as the fluid flows around it, influenced by speed, the surface area, and how streamlined the shape is. That’s why the statement describing drag as the resistance caused by air or water moving over a surface best captures what drag is. The other ideas refer to gravity (weight), metabolic energy cost, or the speed at which an object is projected, none of which describe the resistive fluid force that drag represents.

When an object moves through air or water, the fluid pushes back against that motion. This opposing force is called drag. It’s the resistance the surface experiences as the fluid flows around it, influenced by speed, the surface area, and how streamlined the shape is. That’s why the statement describing drag as the resistance caused by air or water moving over a surface best captures what drag is. The other ideas refer to gravity (weight), metabolic energy cost, or the speed at which an object is projected, none of which describe the resistive fluid force that drag represents.