To calculate the density of an object, you can use the formula:
\[ \text{Density} = \frac{\text{Mass}}{\text{Volume}} \]
First, we need to calculate the volume of the cube. The volume \( V \) of a cube can be calculated using the formula:
\[ V = \text{side length}^3 \]
Given that the side length of the cube is 2 meters:
\[ V = 2 , \text{m} \times 2 , \text{m} \times 2 , \text{m} = 8 , \text{m}^3 \]
Now, we can substitute the mass and the volume into the density formula. The mass of the cube is given as 40 kg.
\[ \text{Density} = \frac{40 , \text{kg}}{8 , \text{m}^3} = 5 , \text{kg/m}^3 \]
Therefore, the density of the cube is \( 5 , \text{kg/m}^3 \).