A 1300 kg car and 4940 kg truck undergo a perfectly inelastic collision. Before the collision, the car was traveling southward at 1.35 m/s, and the truck westward at 9.40 m/s. Find the velocity of the wreckage immediately after the collision. (Enter the x and y components of the velocity separated by a comma. Assume that the positive x and y axes are directed eastward and northward, respectively.)