Physics - NLM Question with Solution | TestHub

Let the acceleration of the system be $a$ and the tension in the string be $T$. For mass $M$ on the table: $T=Ma$. For mass $m$ hanging vertically: $mg-T=ma$. Substituting $T$ from the first equation into the second: $mg-Ma=ma$. So, $mg=(M+m)a$, which gives $a=\frac{mg}{M+m}$.