Question

a rain drop of radius 0.5mm has a terminal velocity in air 2m/s
The viscosity of air is 18x10–5 poise find the viscos force on the
rain drop.​

Answer 1

Explanation:

Here, r=0.3mm=0.03cm,

v=1ms

−1

=100cms

−1

,

η=18×10

−5

poise.

According to stokes law, force of viscosity on rain drop is

F=6πηrv

=6×3.142×18×10

−5

×0.03×100 dyne

=1.018×10

−3

dyne.