Let us assume that a seal's lungs makes up 10% of its bodies volume when full, and that the average density of a seal is 980 kg/m3 when its lungs are full. If the air in the seal's lungs obeys Boyle's law, at what depth would this seal achieve neutral buoyancy in sea water, which has a density of 1020 kg/m3? Assume there are no changes to other tissues in the seal as it dives and that atmospheric pressure is about 1x105 Pa. Before diving, seals may exhale to reduce the amount of air in their lungs. This would increase their density (decreasing their overall volume), and, therefore, reduce their buoyancy so that it is easier for them to dive.]

A. 6.5 m

B.16.5 m

C165 m

D.1.65 m

2. A fish swimming in this lake can lie still at a depth of five meters, without having to exert any upward or downward forces to remain at this depth. The average density of this fish at this depth . is it equal, less than, or greater than the density of the surrounding water?