Question

What is the primary difference between the units of kinematic and dynamic viscosity?

a) Kinematic viscosity is measured in m/s², while dynamic viscosity is in Pa⋅s.
b) Kinematic viscosity is measured in Pa⋅s, while dynamic viscosity is in m/s².
c) Both are measured in m/s².
d) Both are measured in Pa⋅s.

Answer 1

Kinematic viscosity is dynamic viscosity divided by density and measured in m²/s, while dynamic viscosity is the fluid's intrinsic resistance to flow measured in Pa·s.

Step-by-step explanation:

The primary difference between kinematic viscosity and dynamic viscosity is the way each is measured and their units. Dynamic viscosity, denoted by η, measures the fluid's intrinsic resistance to flow and has the unit Pascal-seconds (Pa·s). Kinematic viscosity is dynamic viscosity divided by the fluid's density, and is measured in square meters per second (m²/s). Thus, kinematic viscosity is a measure of the fluid's resistance to flow relative to its density. It's worth noting that the unit of dynamic viscosity, Pa·s, can be broken down into (N/m²)s, which indicates that it's a measure of shear stress (τ, in N/m²) over shear rate (du/dy, in 1/s).