# Two bodies $A$ and $B$ of mass $m$ and $2 m$ respectively are placed on a smooth floor. They are connected by a spring of negligible mass. $A$ third body $C$ of mass $m$ is placed on the floor. The body $C$ moves with a velocity $v_{0}$ along the line joining $A$ and $B$ and collides elastically with $A$. At a certain time after the collision it is found that the instantaneous velocities of $A$ and $B$ are same and the compression of the spring is $x_{0}$. The spring constant $k$ will be

Question:

Two bodies $A$ and $B$ of mass $m$ and $2 m$ respectively are placed on a smooth floor. They are connected by a spring of negligible mass. $A$ third body $C$ of mass $m$ is placed on the floor. The body $C$ moves with a velocity $v_{0}$ along the line joining $A$ and $B$ and collides elastically with $A$. At a certain time after the collision it is found that the instantaneous velocities of $A$ and $B$ are same and the compression of the spring is $x_{0}$. The spring constant $k$ will be

1. $m \frac{v_{0}^{2}}{x_{0}^{2}}$

2. $m \frac{v_{0}}{2 x_{0}}$

3. $2 m \frac{v_{0}}{x_{0}}$

4. $\frac{2}{3} m\left(\frac{v_{0}}{x_{0}}\right)^{2}$

JEE Main Previous Year Single Correct Question of JEE Main from Physics Work, Energy and Power chapter.

JEE Main Previous Year May 12, 2012

Correct Option: 4

Solution:

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