Kinematics

A particle A moves along the line y = d (30 m) with a con­stant velocity v (v = 3.0 m/s) directed parallel to the positive x axis 

in the figure below. A second particle B starts at the origin with zero speed and constant acceleration a (a = 0.40 m/s2

at the same instant that particle A passes the y axis. 

What angle θ between a and the positive y axis would result in a collision between these two particles?