[填空题]
(a) A yo-yo is made of two solid cylindrical disks, each of massnel.ddg5q7 4mql ma *tjq6 /w: 0.09lt;:+ (n4sv zmczdhw kv 3.ho50 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 sk9;hv zt c4 l.h3v:zmwon d(+to calculate the linear speed 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? %