Physics - NLM Question with Solution | TestHub

A frictionless cart of mass M carries two other frictionless carts having masses ${\mathrm{m}}_1$ and ${\mathrm{m}}_2$ connected by a string passing over a pulley as shown in figure. The horizontal force that must be applied on M so that ${\mathrm{m}}_1$ and ${\mathrm{m}}_2$ do not move relative to it will be