A solid object has a weight of $5 \mathrm{N}$. When it is submerged in water, it weighs $3.5 \mathrm{N}$. Find the density of the object. [Density of water = $1\mathrm{x}{10}^3 \mathrm{k}\mathrm{g} {\mathrm{m}}^{-3}$, acceleration due to gravity, $g = 9.8 \mathrm{m} {\mathrm{s}}^{-2}$]