[填空题]
A rotating merry-go-round maw+7rvfkcrvhl ; 9pa)1kes owic4k0n: d5hu tj6;a7a rs+)ok xoiwuj:w) )s ne complete revolution in 4.0 s (Fig. 8–38). (a) What is t:ti5 ))n s;46 d+whju7wkr): jxi uakoaws0cohe 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