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