[问答题]
A large spool of rope roll5k) mvdt).s( 8a xt:6ljpzb tds c 5c-n;rd( zz,z8fu*/cozakt 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, Fig. 8–50. The spool rolls behind the c,- n*(zt;cr/ zzu5kocafz d8person without slipping. What length of rope unwinds from the spool? How far does the spool’s center of mass move?