Question

Two blocks $A$ and $B$ of masses $3m$ and $m$ respectively are connected by a massless and inextensible string. The whole system is suspended by a massless spring as shown in figure. The magnitudes of acceleration of $A$ and $B$ immediately after the string is cut, are respectively :

• A. $\frac{g}{3},g$
• B. $g,g$
• C. $\frac{g}{3},\frac{g}{3}$
• D. $g\frac{g}{3}$

Answer 1

The correct option is A $\frac{g}{3},g$

Before cutting the strip

$T=mg$

after cutting the strip

$a_A=\frac{4mg-3mg}{3m}=\frac{mg}{3m}=\frac{g}{3}$

$a_B=\frac{mg}{m}=g$

$\frac{g}{3},g$.