Physics - Unit & Dimension Question with Solution | TestHub

A spherical body, of mass$m$and radius$r$, is allowed to fall in a medium of viscosity$\mathrm{\eta }$. The time in which the velocity of the body increases from$0$to$0.63$times the terminal velocity$\left(v\right)$is called time constant$\left(\mathrm{\tau }\right)$. Dimensionally$\mathrm{\tau }$can be represented as