A spherical ball of radius $1\mathrm{ }\mathrm{c}\mathrm{m}$ and density $4\times {10}^3 \mathrm{kg} {\mathrm{m}}^{-3}$ is dropped gently in a large container containing a viscous liquid of density $2\times {10}^3 \mathrm{kg} {\mathrm{m}}^{-3}$, and $\mathrm{\eta }=0.1\mathrm{ }\mathrm{N} \mathrm{s} {\mathrm{m}}^{-2}$. The distance moved by the ball in $\mathrm{t}=0.1 \mathrm{s}$ after it attains terminal velocity is