Question

The radii of the two spheres P and Q of same material falling in the viscous liquid are in the ratio 3 : 2, their terminal velocities (P to Q) are in the ratio ______.

Options

• 9 : 4

• 3 : 2

• 2 : 3

• 2 : 9

Answer 1

The radii of the two spheres P and Q of same material falling in the viscous liquid are in the ratio 3 : 2, their terminal velocities (P to Q) are in the ratio 9 : 4.

Explanation:

Terminal velocity v ∝ r²

`"v"_1/"v"_2 = ("r"_1/"r"_2)^2 = (3/2)^2 = 9/4`