A red 2·kg ball traveling 8·m/s due north collides with a green 2·kg ball traveling 5·m/s due west and they stick together. What is the speed of the two stuck-together balls after the collision? m/s. Calling due north 0°, due west 90°, due south 180°, due east 270°, and so on, what direction is he green ball going after the collision?