Fluid Mechanics

A spherical ball of radius $1 \times 10^{-4} \mathrm{~m}$ and of density $10^4 \mathrm{kgm}^{-3}$ falls freely under gravity through a distance $h$ before entering a tank of water. After entering water if the velocity of the ball does not change, then $h$ is
(The coefficient of viscosity of water $9.8 \times 10^{-6} \mathrm{Nsm}^{-2}$ )