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

Monjur Alahi

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.


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Salim Ahmed Kawsar

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(c) the force of viscosity of air balances its weight

Explanation: 

When the raindrop starts falling the force of viscosity of air comes into action. This force is proportional to the velocity. Initially, this force is less than its weight. So there is a net downward force. Thus it accelerates. But a stage comes when due to increased velocity the force of viscosity is equal to its weight. So net downward force now becomes zero. Thus the raindrop keeps falling with a uniform velocity which is called the terminal velocity. 

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