Collision Angle Between Velocities

Particle A of mass m1 moving with velocity (√3

^

i

+

^

j

)ms−1 collides with another particle B of mass m2 which is at rest initially. Let

→

v

1 and

→

V

2 be the velocities of particles A and B after collision respectively. If m1=2m2 and after collision V1=(

^

i

+√3

^

j

)ms−1, the angle between

→

V

1 and

→

V

2 is :