A rain drop of radius 1.5 mm, experiences a drag force $F = (2 imes 10^{- 5}\ v)$ N, while falling through air from a height 2 km, with a velocity$v$. The terminal velocity of the rain drop will be nearly (use $g = 10\ ms^{- 2}$)

Question

A rain drop of radius 1.5 mm, experiences a drag force $F = (2 	imes 10^{- 5}\ v)$ N, while falling through air from a height 2 km, with a velocity$v$. The terminal velocity of the rain drop will be nearly (use $g = 10\ ms^{- 2}$)

Dr. Abubacker · Accepted Answer

(c) When terminal velocity $v$ is reaching, then
$F = 2 	imes 10^{- 5}v = \frac{4}{3}\pi\ r^{3}ho g$
$2 	imes 10^{- 5}v = \frac{4}{3} 	imes \frac{22}{7} 	imes \left( 1.5 	imes 10^{- 3} ight)^{3} 	imes 10^{3} 	imes 10$
On solving, $v = 7.07ms^{- 1} \approx 7ms^{- 1}$

Q. A rain drop of radius 1.5 mm, experiences a drag force $F = (2 \times 10^{- 5}\ v)$ N, while falling through air from a height 2 km, with a velocity$v$. The terminal velocity of the rain drop will be nearly (use $g = 10\ ms^{- 2}$)

Explanation

Reviewed by Dr. Abubacker

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