During a test dive in $1939,$ prior to being accepted by the U$.$S$.$ Navy, the submarine Squalus sank at a point where the depth of water was $73\mathrm{.}0$ m $.$ The temperature at the surface was $27\mathrm{.}0C$ and at the bottom it was $7\mathrm{.}0C.$ The density of seawater is $1030k\frac{g}{m^3}.$