Question

The system of two weights of masses $m_{1}$ and $m_{2}$ are connected with weight less spring as shown. The system is resting on the support $S$ . If the support $S$ is quickly removed then acceleration of each weight just after the removal of $S$ are :-
[Given $\Rightarrow m_{1}=m\&m_{2}=2m$ ]

• A. $a_{1}=gms^{- 2},a_{2}=2gms^{- 2}$
• B. $a_{1}=g/2ms^{- 2},a_{2}=\frac{1}{3}gms^{- 2}$
• C. $a_{1}=0,a_{2}=\frac{3}{2}gms^{2}$
• D. $a_{1}=\frac{2}{3}gms^{- 2},a_{2}=0$

Answer 1

Answer: (C)

$F_{sp}=m_{1}g$
Now if $N=0$ then it will have no effect on $m_{1}$
instantly so $a_{1}=0$ but $m_{2}$ will exp. net
downward force so $\left(m_{2 g} + F_{sp}\right)=m_{2}a_{2}$
$\left(m_{1} + m_{2}\right)g=m_{2}a_{2}$
$\Rightarrow a_{2}=\frac{3}{2}g$