[填空题]
A rotating merry-go-roundn5;,ora y *os;k5 yxfe 3urn3mmp6w*r va4o )uth)a w.makes one complete revolution in 4.0 s (Fig. 8–38). (a) What is the linear speed of a child sea)aa) 4v t.wouhted 1.2 m from the center? $m/s$ (b) What is her acceleration (give components)? $m/s^2$ the center