Question

Two equal drops of water each of radius r are falling through air with a steady velocity of 16 cm/ sec. The two drops combine to forma big drop. Calculate the terminal velocity of the big drop.

Answer 1

Since volume remains constant, hence,

where n = No. of small drops, r = radius of small drop and R = radius of bid drop.

If v₁ and v₂ are the terminal velocities of the small and big drops respectively, then