Final answer:
The density of the rectangular prism is calculated by dividing its mass (140 g) by its volume (70 cm³), resulting in a density of 2 g/cm³.
Step-by-step explanation:
To find the density of the rectangular prism, you must divide the mass of the prism by its volume. First, calculate the volume by multiplying the dimensions of the prism: volume = length × width × height. Using the given dimensions of 2 cm × 5 cm × 7 cm, the volume is 70 cm³. Next, you take the given mass of the prism, which is 140 g, and divide it by the volume to find the density.
Density = mass / volume
Density = 140 g / 70 cm³
Density = 2 g/cm³
Therefore, the density of the prism is 2 g/cm³.