Answer
${\mathrm{RHS}}=\left[{\frac{M L}{T^{2}}}\right]=F$
Work Step by Step
Stokes' law staes:
$\begin{array}{c}{{D=3\pi\mu V D}}\\
{{\mathrm{RHS}=3\pi\left[{\frac{M}{L T}}\right]\left[{\frac{L}{T}}\right][L]}}\end{array}$
$(3\pi)$ is dimensionless
${\mathrm{RHS}}=\left[{\frac{M L}{T^{2}}}\right]=F$
This is the unit of force (newton):
$1\text{ N}=\text{kg}\cdot\text{m/s}^2$
