In rising from the bottom of a lake to the top, the temperature of an air bubble remains unchanged, but its diameter is doubled. If h is the barometric height (expressed in meters of mercury of relative density at the surface of the lake, the depth of the lake is (in meters)
Since the diameter of the bubble is doubled in rising from the
bottom to the top of the lake, its volume becomes 8 times. Now PV = constant.
Therefore, the pressure at the bottom of lake = 8 times that at the top. Let H be the
depth of the lake