A certain playground merry-go-round is essentially an 80-kg iron disk 2.0 m in radius. Two children, each with a mass of 44 kg, are orignally standing on opposite sides of the disk near its outer edge. The merry-go-round is turning essentially without friction about a verticle axis once every 5s. The children then clamber toward each other so that they are only 1.0 m from the center. How long does it take the merry-go-round to complete a revolution now?