[填空题]
(a) A yo-yo is made ohl 5d9o- sh d)v34ablgf3qsq-y dq3y 2jr/e8hl(p 8 rfk two solid 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 reaches the end of its 1.0-m-long string, if it is released from y -q8f ysq2(prl3h qr j/38kedrest. $m/s$ (b) What fraction of its kinetic energy is rotational? %