A child is on a spinning merry-go-round and the child walks to center of it. Is angular momentum preserved if only the child is the system? Is angular momentum preserved if the system is the child and the merry-go-round?

molecules are free to separate from each other and will take on the shape of the container. molecules move completely at random and high speeds. they vibrate in a fixed position and do not move around much. molecules expand to the edge of their container.