Question:
Estimate the speed of vertically falling raindrops from the following data. Radius of the drops $=0.02 \mathrm{~cm}$, viscosity of air $=$ $1.8 \times 10^{-4}$ poise, $g=9.9 \mathrm{~m} / \mathrm{s}^{2}$ and density of water $=1000 \mathrm{~kg} / \mathrm{m}^{3}$.
Solution: