[填空题]
A rotating merry-go-round makes one compleb1c*b y*nmg:w t9hilt (c 2k*afa.:jzo e revolution in 4.0 s (Fig. 8–38). (a) Whathk lt.9a (cifzo2j *:a is the 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