A metal block of base area 0.20 m$^2$ is placed on a table, as shown in figure. A liquid film of thickness 0.25 mm is inserted between the block and the table. The block is pushed by a horizontal force of 0.1 N and moves with a constant speed. IF the viscosity of the liquid is $5.0\times10^{-3}~\mathrm{Pl}$, the speed of block is ____________ $\times10^{-3}$ m/s.