Cart a, with a mass of 0.2 kg, travels on a horizontal air track at 3 m/s and hits cart b, which has a mass of 0.4 kg and is initially at rest. after the collision the center of mass of the two cart system has a speed in m/s of: 0 m/s 1.0 m/s 2.3 m/s 2.5 m/s 5.0 m/s