Question

Give the statement of Stokes' law.

Answer 1

As per the Stoke's law, the force of viscosity on a small sphere moving through a viscous fluid is given by:
$F_d=6\pi \eta Rv$
where:
$F_d$ is the frictional force – known as Stokes' drag – acting on the interface between the fluid and the particle,
$\eta$ is the dynamic viscosity,
R is the radius of the spherical object,
v is the flow velocity relative to the object.