[问答题]
A large spool of rope roll9)o)jhukb7)ioyotq z 2ds4v)sl z;6 9rbc.wgh on the ground with the end of the rope lying on the top edge of the spool. A person grabs the end of the rope and walks a distance L, holding onto it, z;g.w6 hlcr9bFig. 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?