Question

A sphere of radius a, moving with velocity v, under streamline conditions in a viscous fluid experiences a retarding force F, given by F = kav, where k is a constant. What are the base units of k?

Answer 1

$F=[k][a][v]$

$kg.m.s^{-2}=[k](m^{2})(m.s^{-1})$

$[k]=kg.m^{-2}.s^{-1}$