Two balls of equal mass (0.50 kg) approach the origin along the positive x-and y-axes at the

Question:

Two balls of equal mass (0.50 kg) approach the origin along the positive x-and y-axes at the same speed (3.3 m/s).
(a) What is the total momentum of the system?
(b) Will the balls necessarily collide at the origin? What is the total momentum of the system after both balls have passed through the origin?