A 1.0 kg cart travelling at 2.0 m/s [east] collides with a stationary cart, of mass 3.0 kg. The two carts stick together and move off at a constant velocity. Assume that friction is negligible. What is the velocity of the two (connect) carts immediately after the collision? O 0.5 m/s [east] 0 0.67 m/s [east] 0 3.0 m/s [east] O 2.0 m/s [east] 0 6.0 m/s [east]