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प्रश्न
A raindrop falls near the surface of the earth with almost uniform velocity because
विकल्प
its weight is negligible
the force of surface tension balances its weight
the force of viscosity of air balance its weight
the drops are charged and atmospheric electric field balances its weight.
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उत्तर
Air has viscosity. During rainfall, the raindrops acquire acceleration due to gravity. However, the increase in velocity is hindered by the viscous force acting upwards. A gradual balance between the two opposing forces causes the raindrops to attain a terminal velocity, thus, falling with a uniform velocity.
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