Mathematics · Fluid Mechanics

A raindrop with radius R = 0.2 mm falls from a cloud at a height h = 2000 m above the ground. Assume that the drop remains spherical throughout its fall and the force of buoyancy may be neglected. The terminal speed attained by the raindrop is: [Density of water ρw = 1000 kg m-3, Density of air ρa = 1.2 kg m-3, g = 10 m/s2, and Coefficient of viscosity of air η = 1.8 × 10-5 N s m-2]