Why not rain drops do not posses greater velocity than some velocity ? Explain.
Since the rain drop freely falling under the gravitational force. The other force is the air resistance exerted opposite to its motion. As the velocity increases resultant force on it decreases. If a resultant force for certain velocity $\left[\mathrm{F}(v)=\frac{4}{5} \pi r^{3}(\rho-\sigma) g-\sigma \pi \eta r v\right]$ becomes zero, then its velocity becomes constant which is known as terminal velocity. From now velocity of drop does not increases.
Velocity of water in a river is
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