Two small particles of equal masses start moving in opposite directions from a point in a horizontal circular orbit. Their tangential velocities are and , respectively, as shown in the figure. Between collisions, the particles move with constant speeds. After making how many elastic collisions, other than that at , these two particles will again reach the point

The correct answer is: 2

Let initially particle is moving in anticlockwise direction and in clockwise direction
As the ratio of velocities of and particles are , therefore ratio of their distance covered will be in the ratio of . It means they collide at point B

After first collision at B, velocities of particles get interchanged, ., will move with and particle with
Second collision will take place at point C. Again at this point velocities get interchanged and third collision take place at point A
So, after two collision these two particles will again reach the point A