A block of weight 100N is pushed by a force F on a horizontal rough plane moves with an acceleration 1$\mathrm{m}/{\mathrm{s}}^2$  ,when force is doubled its acceleration becomes $10\mathrm{m}/{\mathrm{s}}^2$ .The coefficient of friction is ______ $\left(\mathrm{g}=10{\mathrm{ms}}^{-2}\right)$