Two hockey pucks, labeled A and B, are initially at rest on a smooth ice surface and are separated by a distance of 18.0 m . Simultaneously, each puck is given a quick push, and they begin to slide directly toward each other. Puck A moves with a speed of 3.10 m/s , and puck B moves with a speed of 3.50 m/s . What is the distance covered by puck A by the time the two pucks collide?