In a simple concentric shaft-bearing arrangement, the lubricant flows in the $2$ $mm$ gap between the shaft and the bearing. The flow may be assumed to be a plane Couette flow with zero pressure gradient. The diameter of the shaft is $100$ $mm$ and its tangential speed is $10$ $m/s$. The dynamic viscosity of the lubricant is $0.1$ $kg/m.s$. The frictional resisting force (in newton) per $100$ $mm$ length of the bearing is _______