A boy of mass $M$ is applying a horizontal force to slide a box of mass $M^{\prime}$ on a rough hori

Question

A boy of mass $M$ is applying a horizontal force to slide a box of mass $M^{\prime}$ on a rough horizontal surface. The coefficient of friction between the shoes of the boy and the floor is $\mu$ and that between the box and the floor is $\mu^{\prime}$. In which of the following cases it is certainly not possible to slide the box ?

Professor PC Thomas Classes · Answer

See detailed solution for explanation.