[填空题]
A rotating merry-go-round makes oq9:hl .va +grb+5: vx*wfh kmbne complete revolutioa jsaj e5:srbd4,u9g 3n in 4.0 s (Fig. 8–38). (a) Whau4ds 3j9 a:jbar, sg5et is the linear speed of a child seated 1.2 m from the center? $m/s$ (b) What is her acceleration (give components)? $m/s^2$ the center