[填空题]
(a) A yo-yo is made of two solid cylindrica,ve bazpvvj 8)s)b/zk6g8 d: cl disks, e auq lc-zyjfj24+k1n5ach of mass 0.050 kg and diameter 0.075 m, joined by a (concentric) thin solid cylindrical hub of mass 0.0050 kg and diameter 0.010 m. Use conservation of energy to calculate the linear cun4yj5kz aq 1-+j2flspeed of the yo-yo when it reaches the end of its 1.0-m-long string, if it is released from rest. $m/s$
(b) What fraction of its kinetic energy is rotational? %