A small spherical ball of radius 0.1 mm and density 10⁴ kg m^-3 falls freely under gravity through a distance 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 h will be________m

(Given, $\mathrm{g}=10{\mathrm{ms}}^{-2}$, viscosity of water $=1.0\times {10}^{-5}\mathrm{N}-{\mathrm{sm}}^{-2}$)