Solution

Calculate the terminal velocity of a spherical raindrop with a radius $0.5\,\mathrm{mm}$ falling through the air. ($\eta$ for air $= 19 \times 10^{-6}\,\mathrm{kg\,m^{-1}\,s^{-1}}$, $\rho = 1000\,\mathrm{kg\,m^{-3}}$ for water)