Question

The system shown in the figure is in equilibrium and at rest. The spring and string are massless, now the string is cut. The acceleration of mass $2 \, m$ and $m$ just after the string is cut will be

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

Answer 1

Answer: (A)

Initially under equilibrium of mass $m$
$T=mg$
Now, the string is cut. Therefore, $T=mg \, $ force is decreased on mass $m$ upward and downwards on mass 2 $m.$
$\therefore \, a_{m}=\frac{m g}{m}=g \, \left(d o w n w a r d s\right)$
and $ \, a_{2 m}=\frac{m g}{2 m}=\frac{g}{2} \, \left(\right.upwards\left.\right)$