[填空题]
A rotating merry-go-round makes one complete8 i5pkzc9hnfi73 pb.o regkp0hg38e j1a9eth l .volution in 4.0 s (Fig. 8–38). (a) What is the linear speed of a child seated 1.h0taekh 3j gp eg981l.2 m from the center? $m/s$ (b) What is her acceleration (give components)? $m/s^2$ the center