Physics help needed: Find speed before and after collision.?

A 1 kg mass is moving at an original speed 5 m/s toward the right. It collides elastically with a 2 kg mass that is initially at rest. The small mass moves off after the collision at a speed v_1, at an angle of 30degrees. The big mass moves off after the collision at a speed of v_2, at an angle of theta_2. Calculate the values of v_1, v_2, and theta_2.