Physics - NLM Question with Solution | TestHub

$m_1=4\mathrm{kg},m_2=2\mathrm{kg}$, friction coefficient between the blocks $m_1\&m_2$ is $\mu =0.4\&\mathrm{g}=10\mathrm{m}/{\mathrm{s}}^2$. Find $\mathrm{M}(\mathrm{kg})$ for which ${\mathrm{m}}_2$ will start sliding over ${\mathrm{m}}_1$. (Ground is frictionless)