Question

A small spherical solid ball is falling down in a viscous liquid. Its velocity in the viscous liquid is best represented by the curve:

• A. D
• B. C
• C. B
• D. A

Answer 1

Answer: (B)

The velocity of a sphere falling in a liquid increases at first. This continues to increases under opposing buoyant and viscous force. Viscous force is proportional to the velocity of the ball. As the speed increases with distance, opposing force tends to increase and the velocity finally tends to reach a terminal velocity at infinite time. Here it is best represented by curve C.