Question

Two blocks $A$ and $B$ of masses $2m$ and $m$, respectively are connected by a massless and inextensible string. The whole system is suspended by a massless spring as shown in the figure. The magnitudes of acceleration of A and B immediately after the string is cut, are respectively

• A. $g, \frac{g}{2}$
• B. $\frac{g}{2}, g$
• C. $g, g$
• D. $\frac{g}{2}, \frac{g}{2}$

Answer 1

Answer: (B)

After string is cut, free body diagram of block A gives

$2ma_{A}=3mg-2mg$
or $a_{A}=\frac{mg}{2m}=\frac{g}{2}$
Free body diagram of block B gives
$ma_{B}=mg$
or $a_{B}=g$