A spring with spring constant $35 \mathrm{N} / \mathrm{m}$ is attached to the ceiling, and a 5.0 - cm-diameter, $1.0 \mathrm{kg}$ metal cylinder is attached to its lower end. The cylinder is held so that the spring is neither stretched nor compressed, then a tank of water is placed underneath with the surface of the water just touching the bottom of the cylinder. When released, the cylinder will oscillate a few times but, damped by the water, quickly reach an equilibrium position. When in equilibrium, what length of the cylinder is submerged?