[填空题]
A rotating merry-go-round makes one complet sslddia 5-/nt., g+07 :ushpvpnds g/e revolution in 4.0 s (Fig. 8–38). (.f fe8qzf iw;wbj4*3pa) What is the linefpwf .4wq;ebzfij 8*3ar 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