Two cars moving in opposite directions end up in a head-on collision. The larger car has a mass of 3000 kg and the smaller car has a mass of 1000 kg and they are both moving at a speed of 20 m/s when the collision takes place. After the crash, the two vehicles stick and move together with a common speed. (A) Draw a simple picture clearly labeling the two vehicles, their directions of motion and their velocities, before the crash. Clearly mark the 'positive' direction of motion. (B) Calculate the velocity of the two-car system right after the accident.