Viscosity

Definition

Viscosity refers to the measure of a fluid's resistance to flow. It describes how thick or sticky a fluid is, and determines how easily it can be poured or moved.

Analogy

Imagine trying to pour honey out of a jar versus pouring water from a glass. Honey has high viscosity because it is thick and flows slowly, while water has low viscosity because it is thin and flows quickly.

Related terms

Shear Stress: Shear stress is the force per unit area that causes one layer of fluid to slide past another layer. It is directly related to viscosity.

Newtonian Fluid: A Newtonian fluid is a type of fluid that follows Newton's law of viscosity, where the shear stress is directly proportional to the rate of deformation.

Non-Newtonian Fluid: A non-Newtonian fluid does not follow Newton's law of viscosity and its behavior depends on factors like pressure, temperature, or applied force. Examples include ketchup and toothpaste.