posted by Amy .
assuming that sea water has a density of 1.05 g/cm^3, what is the density of a submarine running submerged?
wouldn't you need to know some other information; like the mass or volume of the submarine?
No. The average density of the submarine would have to be the same as the surrounding fluid, if it is neither rising nor sinking.
Think of the Archimedes Law and you should see why this is so.