Which of the following describes fluid friction?

Fluid friction specifically refers to the resistance encountered by an object as it moves through a fluid, which can be a liquid or gas. This type of friction arises because the surface of the object interacts with the molecules of the fluid, causing drag that opposes the motion. The force of fluid friction is influenced by the speed of the object, its shape, and the viscosity of the fluid.

When considering other types of friction, such as that experienced by static objects, rolling objects, or sliding objects, these do not involve a fluid medium. Static friction prevents motion until a certain threshold is reached, rolling friction occurs when an object rolls over a surface (like a wheel on a road), and sliding friction happens when an object moves across a surface. Each of these specific friction types operates under different principles and contexts, making them distinct from fluid friction, which is uniquely focused on the motion through a fluid.