viscous resistance

Viscous resistance is the force that opposes the flow of a fluid, like water or oil, as it moves through a space or over surfaces. It happens because molecules within the fluid stick to each other and to surfaces, creating friction. This resistance depends on the fluid's thickness or viscosity—the higher the viscosity, the greater the resistance. For example, honey resists flowing more than water. In practical terms, viscous resistance affects how easily fluids move through pipes, around objects, or within machines, impacting efficiency and performance.