What happens to plates in the mantle? ( can someone plz answer its really important! ) a) they stay fixed in one place b) they all float in one direction c) only some float around d) they all float around in various directions.

Aplayground merry-go-round has a radius of 4.6 m and a moment of inertia of 200 kg-m2 and turns with negligible friction about a vertical axle through its center. a child applies a 26.0 n force tangentially to the edge of the merry-go-round for 15.0 seconds. if the merry-go-round is initially at rest, how much work did the child do on the merry-go-round?