[填空题]
A rotating merry-go-round makes onl+b3 fkp8a;+sy59uwllt6k3ts 9tpoq 1i 0 ap esm- 7phb 9jhb(e complete revolution in 4.0 s (Fig. 8–38). (a) What is the linear speed of a child seated bs9m-(ph7h jb 1.2 m from the center? $m/s$ (b) What is her acceleration (give components)? $m/s^2$ the center