Consider two concentric thin wall steel tubes, the larger one closed at the bottom and the inner one open. The tubes are filled with a fluid. A well fitting cylinderical plug that slides easily is dropped in the inner tube and a well fitting annular ring (doughnet) which slides easily is dropped between the two tubes. The weights of both plugs are the same. After osillating a litle the plugs settle concentrically with one another another as shown. What must be the relationships between the radii of the tubes.