A small spherical ball of radius 0.1 mm and density 10^4 kg m^-3 falls freely under gravity through a distance h before entering a tank of water. If,…

A small spherical ball of radius $\displaystyle 0.1$ mm and density $\displaystyle 10^4 \mathrm{~kg} \mathrm{~m}^{-3}$ falls freely under gravity through a distance $\displaystyle h$ before entering a tank of water. If, after entering the water the velocity of ball does not change and it continue to fall with same constant velocity inside water, then the value of $\displaystyle h$ will be \_\_\_\_ m (Given $\displaystyle g=10 \mathrm{~ms}^{-2}$, viscosity of water $\displaystyle =1.0 \times 10^{-5} \mathrm{~N}-\mathrm{sm}^{-2}$ ).