[填空题]
A rotating merry-go-round makes one complete re1 itx7(cpymz3ej -ns5w 9g 2 imn(wp(ivolution in 4.0 s (Fig. 8–38).5x7 m+a uqf345 a0kpqfp y,slq (a) What is the linear speed of a child seated 1pafa30+5m sqf x5uqylpk7,4 q.2 m from the center? $m/s$ (b) What is her acceleration (give components)? $m/s^2$ the center