[填空题]
A rotating merry-go-round mwpsoee2q-o (* akej f1 jr da1b5+x8jvcw)r,y w,js one complete revolution in 4.0 s (Fig. 8–38). (a) What is the linear speed of a 5brvw1x jr ,a)f dj1jcy8+ wj,child seated 1.2 m from the center? $m/s$ (b) What is her acceleration (give components)? $m/s^2$ the center