The hull of a ship is often subdivided into watertight compartments to prevent the ship's sinking from a single puncture of the hull. Consider a rectangular compartment with a floor area of 500 ft and a doorway with a sill 0.5 ft above the floor of the compartment. If water flows through a puncture in the hull ata rate of 90,000 gal/min, how long will it take for water to begin to flow through the doorway?