Vízkozita

Vízkozita is a fundamental property of fluids that describes their resistance to flow. It is essentially a measure of a fluid's internal friction. Imagine two layers of fluid moving past each other. Viscosity quantifies the force required to overcome the friction between these layers.

The concept of viscosity is closely related to the intermolecular forces within a fluid. In liquids, viscosity generally decreases with increasing temperature because the kinetic energy of the molecules overcomes the attractive forces more easily, allowing them to slide past each other with less resistance. Conversely, for gases, viscosity typically increases with temperature as molecular collisions become more frequent and energetic, leading to greater momentum transfer between layers.

Viscosity is often expressed in units such as the Pascal-second (Pa·s) or the poise (P). Newton's law of viscosity describes the relationship between shear stress, shear rate, and viscosity for Newtonian fluids. In such fluids, the viscosity is constant regardless of the applied shear stress. However, many fluids, like ketchup or paint, exhibit non-Newtonian behavior, where their viscosity changes depending on the applied stress or shear rate. This property has significant implications in various fields, including engineering, manufacturing, and everyday phenomena like pouring liquids.