a rain drop of radius 0.3mm has a terminal velocity in air 1m/s. the viscosity of air is 18×10^-5 dyne cm^-2 s. find the viscous force on the rain drops in newton.

Answer 1

F=6pie.n.r.v
=6*(3.14)*18*10^-5*0.3*10^-3*1
=1017.3*10^-4N