[填空题]
A rotating merry-go-round makes one 3n na+3 02ndk5be etxdoo*i.scomplete re fj 1qtmckyk;. 65sp,hvolution in 4.0 s (Fig. 8–38). (a) What is the linear speed of a child seated 1.2 m from th5, kq1pyst mj6;cf k.he center? $m/s$ (b) What is her acceleration (give components)? $m/s^2$ the center