A raindrop with radius R = 0.2 mm falls from a cloud at a height h = 2000 m above the ground. Assume that the drop is spherical throughout its fall and the force of buoyance may be neglected, then the terminal speed attained by the raindrop is :
[Density of water f
w
= 1000 kg m
$-3
and Density of air f
a
= 1.2 kg m
-3
, g = 10 m/s
2
, Coefficient of viscosity of air = 1.8 \times 10
-5
Nsm
-$2
]