Two 125 kg bumper cars are moving toward each other in opposite directions. Car X is moving at 10 m/s and Car Z at –12 m/s when they collide head–on. If the resulting velocity of Car Z after the collision is 10 m/s, what is the velocity of Car X after the collision?
–12 m/s
–10 m/s
10 m/s
12 m/s