In order to calculate the density of the block, we must calculate its volume first.
The volume of the block is given by:
[tex] V=5.10 cm \cdot 2.50 cm \cdot 1.15 cm =14.66 cm^3 [/tex]
So now we can calculate the density of the block as the ratio between its mass and its volume:
[tex] d=\frac{m}{V}=\frac{39.589 g}{14.66cm^3}=2.7 g/cm^3 [/tex]