A tall black plastic cylinder with a diameter of 25cm is fitted with a 2kW heating element. It is found that heat is lost only from the outside surface of the part of the cylinder that is filled with water. What is the maximum depth to which the cylinder can be filled by water and still reach boiling point? Ignore the radiation impinging on the cylinder from the room, and the radiation from the bottom of the cylinder a) 1.2 m b) 2.3 m c) 4.6 m d) 7.0 m e) 449 m