[填空题]
(a) A yo-yo is made of two solid cylindrical disks, each g7d5g;yv 1maj of mass 0.0es 00dyo40 3 n(esqkan x)tsq*50 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-looks dt30eqns0 a yq)es n(*x04ng string, if it is released from rest. $m/s$ (b) What fraction of its kinetic energy is rotational? %