Question

In the given figure, spring block system is in equilibrium. The spring connecting blocks $A$ and $B$ is cut. The mass of all the three blocks is m and spring constant of both the spring is $k$ . Find the amplitude of resulting oscillation of block $A$ ?

• A. $\frac{m g}{k}$
• B. $\frac{2 m g}{k}$
• C. $\frac{3 m g}{k}$
• D. $\frac{4 m g}{k}$

Answer 1

Answer: (B)

At equilibrium, the elongation in spring $= \frac{3 m g}{k}$ . After the string is cut, only mass m is hanging. The elongation at equilibrium is $\frac{m g}{k} .$ Hence amplitude is $\frac{3 m g}{k} . - \frac{m g}{k} = \frac{2 m g}{k} .$