On a frictionless horizontal surface , assumed to be the x−y plane , a small trolley A is moving along a straight line parallel to the y−aξs( see figure) with a constant velocity of (3–√−1)m/s . At a particular instant , when the line OA makes an angle of 45(∘) with the x−aξs , a ball is thrown along the surface from the origin O. Its velocity makes an angle ϕ with the x−axis and its hits the trolley