Written by the Fiveable Content Team • Last updated September 2025
Written by the Fiveable Content Team • Last updated September 2025
Definition
Viscous drag is the resistance experienced by an object moving through a fluid due to the fluid's viscosity. It acts opposite to the direction of the object's motion and increases with speed.
5 Must Know Facts For Your Next Test
Viscous drag is proportional to the velocity of the object for laminar flow, described by Stokes' Law: $F_d = 6 \pi \eta rv$.
For turbulent flow, viscous drag depends on the square of the velocity and is generally more complex to model.
The viscosity of a fluid is a measure of its resistance to deformation and plays a key role in determining viscous drag.
In biological systems, viscous drag affects processes like blood flow in arteries and air flow in respiratory tracts.
Drag coefficient ($C_d$) is a dimensionless number that represents an object's resistance to fluid flow and factors into calculating viscous drag.
A type of fluid movement characterized by chaotic changes in pressure and flow velocity.
Stokes' Law: $F_d = 6 \pi \eta rv$, describing the force of friction experienced by spherical objects moving through a viscous fluid at low velocities.