[填空题]
(a) A yo-yo is made of two solid2g0ipj jns 3vxka ;v52 cylindrical disks, each of mass 0.050 kg and h; yt2f gffey197zc 4bdiameter 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-tcy eyzh19;g4bff 27flong string, if it is released from rest. $m/s$ (b) What fraction of its kinetic energy is rotational? %