Physics - NLM Question with Solution | TestHub

Two bodies of mass $m$ and $4m$ are attached by a string as shown in the figure. The body of mass $m$ hanging from a string of length $l$ executes simple harmonic motion with amplitude $A=\frac{l}{2}$ while the other body is at rest on the horizontal surface. The minimum coefficient of friction between the mass $4m$ and the surface to keep it at rest is: