[填空题]
(a) A yo-yo is made of two solid cylindricalhki w)) (dsn8(*vexjl disks, ea) +f*nw-q0wc ,5zn- zrvj+2c8lbzc hxkqwa d)ch 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 nzc dw-+2krxqz 8 qfa*)w)c,+h 5vjcw-0 blnzreaches 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? %