in the days before scuba gear, some divers descended to underwater depths in diving bells, which are basically just upside-down containers whose open ends face down (towards the water; see the illustration below). the bell allows the person inside to breathe the air trapped inside it, observe underwater objects and marine life, and work under the water. if the bell is submerged to a depth of 30m below sea level, what is the water pressure at the air-water interface inside the bell? (