Three point like equal masses `m_(1), m_(2)` and `m_(3)` are connected to the ends of a massless rod of length `L` which lies at rest on a smooth horizontal plane. At `t = 0`, an explosion occurs between `m_(2)` and `m_(3)`, and as a result, mass `m_(3)` is detached from the rod, and moves with a known velocity v at an angle of `30^(@)` with the `y`-axis. Assume that the masses `m_(2)` and `m_(3)` are unchanged during the explosion. What is the velocity of the centre of mass of the system consisting of three masses, after the expulsion?

Options

A. `v/4(hati-3hatj)`
B. `v/4(-hati+sqrthatj)`
C. `-v`
D. none of these

Answer

D

Explanation

As no external force acts, so centre of mass remins at rest.