Question

A sphere of mass M and radius R is falling in a viscous
fluid. The terminal velocity attained by the falling
object will be proportional to
(1) MR
(2) M/R
(3) MR
(4) M/R2​

Answer 1

Explanation:

Vo = 2/9 R³(ρ - ρ')g/Rη

But,

m = 4/3 πR³ρ or m ∝ R³

Hence, Vo = M/R