Fluid friction, also known as viscous drag, is the force that opposes the motion of an object through a fluid (liquid or gas). It occurs due to the interactions between the molecules of the fluid and the surface of the object moving through it. Fluid friction is an important concept in the study of fluid dynamics and has practical applications in various fields including engineering, physics, and biology.
Engineers and scientists often seek to minimize fluid friction in order to improve the efficiency of various systems. Some methods for reducing fluid friction include:
Streamlining the shape of an object to reduce drag
Make observations of plants and animals to compare the diversity of life in different habitats[Clarification Statement: Emphasis is on the diversity of living things in each of a variety of different habitats.] [Assessment Boundary: Assessment does not include specific animal and plant names in specific habitats.]