Center of Mass

Particle A of mass m₁ moving with velocity $\left( {\sqrt3\widehat i + \widehat j} \right)m{s^{ - 1}}$ collides with another particle B of mass m₂ which is at rest initially. Let $\overrightarrow {{V_1}}$ and $\overrightarrow {{V_2}}$ be the velocities of particles A and B after collision respectively. If m₁ = 2m₂ and after collision $\overrightarrow {{V_1}} =$$\left( {\widehat i + \sqrt 3 \widehat j} \right)$ , the angle between $\overrightarrow {{V_1}}$ and $\overrightarrow {{V_2}}$ is :