What does viscosity measure in a fluid?

Viscosity is a crucial property of fluids that quantifies their resistance to flow. In practical terms, it refers to how thick or thin a liquid is; for instance, honey has a high viscosity compared to water, meaning honey flows more slowly. This resistance is influenced by the internal friction between the layers of the liquid as they move over one another. Understanding viscosity is essential in beauty therapy, especially when dealing with products like creams, lotions, and oils, as it affects how easily they spread and absorb into the skin.

In this context, other options do not accurately describe viscosity. The temperature at which a fluid freezes pertains to its freezing point, while density measures the mass of a substance per unit volume. The amount of dissolved solids is related to the substance’s concentration rather than its flow characteristics. Thus, focusing on viscosity as the measure of resistance to flow provides a clear and relevant understanding of fluid behavior in beauty therapy applications.