How does the terminal velocity ($vt$) of a small spherical body falling through a viscous fluid depend on its radius ($r

Question

How does the terminal velocity ($vt$) of a small spherical body falling through a viscous fluid depend on its radius ($r$)?

Accepted Answer

According to Stokes' Law, terminal velocity is given by $vt = \frac{2}{9}\frac{r^2(ho - \sigma)g}{
eta}$. Therefore, $vt \propto r^2$.

Mechanical Properties of Fluids