[填空题]
(a) A yo-yo is made of two solid cylindrical disks,9d4nhd s ott5-16kaig8o 0jbe:c;b y7ooareeh- n6.m(t o g1veach of mass 0.050 kg and diameter 0.075 m, joined by a (concentric) hy:67te oag(m-1onr.ov bec; 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 rest. $m/s$ (b) What fraction of its kinetic energy is rotational? %