Two small spherical metal balls, having equal masses, are made from materials of densities ρ_1 and ρ_2 (ρ_1=8 ρ_2) and having radii of 1 mm and 2 mm,…

Two small spherical metal balls, having equal masses, are made from materials of densities $\displaystyle \rho_1$ and $\displaystyle \rho_2$ $\displaystyle \left(\rho_1=8 \rho_2\right)$ and having radii of $\displaystyle 1$ mm and $\displaystyle 2$ mm, respectively. They are made to fall vertically (from rest) in a viscous medium whose coefficient of viscosity equals $\displaystyle \eta$ and whose density is $\displaystyle 0.1 \rho_2$. The ratio of their terminal velocities would be,