Two spheres A and B of masses m1 and m2 respectively collide. A is at rest initially and B is moving with velocity v along x-axis. After collision B has a velocity v/2 in a direction perpendicular to the original direction. The mass A moves after collision in the direction ;

θ = tan^-1(-1/2) to the x-axis

In x- direction : m₂ v = m₁v₁ cos θ ….(i)

In y- direction : m₂ v/2 + m₁v₁ sin θ = 0 …(ii)

tan θ/2 = -1/2