Two hockey players, Aaron and Brunnhilde, are pushing two pucks on a frictionless ice rink. The pucks are initially at rest on the starting line. (Figure 1) Brunnhilde is pushing puck B, which has a mass three times as great as that of puck A, which Aaron is pushing. The players exert equal constant forces of magnitude on their pucks, directed horizontally, towards the finish line. They start pushing at the same time, and each player pushes his or her puck until it crosses the finish line, a distance away.