Question

Density is a measure of the mass per unit of volume for a material. Mathematically, this can be expressed in units of kg/m3. Given that the equation for the volume of sphere is based on radius, the density of Earth is ___x10³ kg/m³

Answer 1

Let's first find the volume of Earth:

$$V=\dfrac{4}{3}\pi r^3=\dfrac{4}{3}\pi\times(6.37\times10^6\ m)^3=1.08\times10^{21}\ m^3.$$

Finally, we can find the density of Earth:

$$\rho=\dfrac{m}{V}=\dfrac{5.98\times10^{24}\ kg}{1.08\times10^{21}\ m^3}=5.537\times10^3\ \dfrac{kg}{m^3}.$$