Raindrop Terminal Velocity and Force Balance – Rankers Physics

Surface Tension and Viscosity: Practice Problem & Solution

Assertion (A): A raindrop after falling through some height attains a constant velocity. Reason (R): At constant velocity the viscous drag plus buoyant force is just equal to its weight.  
(1) Both (A) & (R) are true and the (R) is the correct explanation of the (A)
(2) Both (A) & (R) are true but the (R) is not the correct explanation of the (A)
(3) (A) is true but (R) is false
(4) Both (A) and (R) are false

Short Solution (Best for NEET):

To solve this problem, we apply the core principles of Surface Tension and Viscosity. Understanding the underlying formula is key to arriving at the correct answer below:

Assertion (A) is true, as falling objects in a fluid reach terminal velocity when resistive forces balance gravity.

Reason (R) is true, stating the force balance condition for constant velocity: Weight = viscous drag + buoyant force. (R) correctly explains (A).

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