A boy of mass 4 kg is standing on a piece of wood having mass 5 kg. If the coefficient of friction between the wood and the floor is 0.5, the maximum…

A boy of mass $\displaystyle 4$ kg is standing on a piece of wood having mass $\displaystyle 5$ kg. If the coefficient of friction between the wood and the floor is $\displaystyle 0.5$ , the maximum force that the boy can exert on the rope so that the piece of wood does not move from its place is \_\_\_\_ N. (Round off to the Nearest Integer) [Take $\displaystyle \mathrm{g}=10 \mathrm{~ms}^{-2}$ ]