A diagram shows an axle of radius R that is mounted so that it is free to rotate. Two pulleys are welded to the axle (i.e., when the pulleys turn, the axle turns with them). One pulley has radius 4R and the other has radius 8R. Three ropes are wound around the axle and pulleys and are fastened to three objects of masses m, 2m and 3m as shown. Which of the three wheels are spinning the quickest?