Question

64 equal drops of water are falling through air with a steady velocity V₀, if the drops coalesce, what is their new velocity? 

(A) 4 V₀ 

(B) 2^{{(– 1) / 3}} V₀ 

(C) 2 V₀ 

(D) 2^(1/3) V₀

Answer 1

The correct option is (A) 4 V_0.

Explanation:

∵ Mass will remain same

 ∴ ρ × (4/3)πr³ × 64 = (4/3)πR³ × ρ

Where R is radius of new drop and r is radius of small drop