Question

A raindrop falls near the surface of the earth with almost uniform velocity because:

• A. its weight is negligible.
• B. the force of surface tension balances its weight.
• C. the force of viscosity of air balances its weight.
• D. the drops are charged and atmospheric electric field balances its weight.

Answer 1

Answer: (C)

the force of viscosity of air balances its weight.

Gravity does cause things to fall with increasing speed, but as they speed up viscous force due to air increases. Eventually the viscous force due to air is enough to balance the force of gravity, so the acceleration stops and the raindrop reaches a constant terminal velocity.