Two cars approach an intersection which is covered in ice (and frictionless). The first car of mass m1 = 1400 kg is heading due east with an initial velocity of 29 m/s and the second car of mass m2 = 3100 kg is heading due north with an initial velocity of 30 m/s. What is the magnitude of the velocity of the two cars after they collide and stick together

Two cars approach an intersection which is covered in ice (and frictionless). The first car of mass m1 = 1400 kg is heading due east with an initial velocity of 29 m/s and the second car of mass m2 = 3100 kg is heading due north with an initial velocity of 30 m/s. What is the magnitude of the velocity of the two cars after they collide and stick together