[填空题]
(a) A yo-yo is made of mv;l(ht0 bu3stwedrt,0jr5 v+p*vdgk +o 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 rest. jt, 5vp rg+ke*+rvd0d $m/s$ (b) What fraction of its kinetic energy is rotational? %