Two swimmers a and b, of weight 190 lb and 125 lb, respectively, are at diagonally opposite corners of a floating raft when they realize that the raft has broken away from its anchor. swimmer a immediately starts walking toward b at a speed of 2 ft/s relative to the raft. knowing that the raft weighs 300 lb, determine (a) the speed of the raft if b does not move, (b) the speed with which b must walk toward a if the raft is not to move.