[填空题]
A rotating merry-go-round ua i:h6cmj ci,6sr ddp-b(tz ;ed4l31y*croxwkytcwl+p v :3-j(:4 mmakes one complete revolution in 4.0 s (Fig. 8–38). (a) What is the linear speed of a wl (o:t*cmx 3yr:-v4p j+ckyw child seated 1.2 m from the center? $m/s$ (b) What is her acceleration (give components)? $m/s^2$ the center