[问答题]
A large spool of rope roll hdyg:pxq58:ms on the ground with thebyl t,qo6 5wl6+ /xkwxdr7 iuhor2t 81 end of the rope lying on the top edge of the spool. A person grabs the end of the rope and walks a distance+ly6 2w5xh6xwr7u/tlok1qb 8o ,rtdi L, holding onto it, Fig. 8–50. The spool rolls behind the person without slipping. What length of rope unwinds from the spool? How far does the spool’s center of mass move?