Question

Bill has a perfect cube of an unknown substance. The density of the substance is 3.0 g/cm. He

Answer 1

The volume of the cube of unknown substance is $27\ cm^3$. The length of one side of the cube is 9 cm

Explanation:

As per the formula of mass and density, Mass / Density equals to volume. Therefore as the mass of the cube was given to be 81 g and the density of the cube is known to be 3.0 g/$\mathrm{cm}^{3}$,, to help Bill find out the volume. It is the ratio of mass and density and can be calculated as

      $\text {volume}=\frac{\text {mass}}{\text {density}}=\frac{81 g}{3 g / \mathrm{cm}^{3}}=27 \mathrm{cm}^{3}$

As it is a cube, the volume is product of length, breadth, and height. Here, all sides are same as it is the cube.

        $volume= length \times breadth \times height$

       $27=3 l$

      $length of cube's one side, l=\frac{27}{3}=9 \mathrm{cm}$