Abody 'a' of mass 1.5kg travelling along the positive x-axis with speed of 4.5m/s collides with another body 'b' of mass 3.2kg, which initially is at rest as a result of the collision, 'a' is deflected and moves in a speed of 2.1m/s in a direction which is at an angle of 30 degree below the x-axis. 'b' is set in motion at an angle φ above the x-axis. calculate the velocity of 'b' after the collision.