[填空题]
(a) A yo-yo is made of t-h/ecm/9qs,e 4nwoom t )r nw2wo ssp m3yoz(l0db sg4o,2olid cylindrical disks, each 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 speed of the yo-yo when it reach4byss,o z3pl0md g(o2es 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? %