[tex]l=4 \ cm=0,04 \ m \\ m=499,2 \ g=0,4992 \ kg \\ \boxed{\rho-?} \\ \bold{Rezolvare:} \\ \boxed{\rho= \frac{m}{V} } \\ V=l^3=(0,04 \ m)^3=0,000 \ 064 \ m^3 \\ \rho= \frac{0,4992 \ kg}{0,000 \ 064 \ m^3} \\ \Rightarrow \boxed{\rho=7 \ 800 \ kg/m^3 \to \boxed{otel \ sau \ fier}}[/tex]
