two seimming teams are competing 400 meter medley relay during last leg race swimmer

Two seimming teams are competing in a 400 meter medley relay. During the last leg of the race, the swimmer in lane one is swimming 1.8 meters per second with a 1.2 second head start. The swimmer in lane 2 in going 1.9 meters per second. After how many seconds into the leg will the swimmer in lane 2 catch up to the swimmer in lane 1