Fluid Mechanics

What is the terminal velocity of a rain drop of radius 0.02 mm ?

[Note that the coefficient of viscosity of air is $1.8 \times 10^{-5} \mathrm{N} / \mathrm{m}^2$, density of water is $1000 \mathrm{~kg} / \mathrm{m}^3$. Use, $g=10 \mathrm{~m} / \mathrm{s}^2$ and density of air can be neglected in comparision with density of water]