Question

The mass of the Earth is 6.45c10^24kg and it's radius is 3.38x1010. compute the density of the earth using power of ten notation

Answer 1

$$\rho=\frac{m}{V}=\frac{m}{\frac{4\pi r^3}{3}}$$

$$\rho =\frac{3m}{4\pi r^3}$$

$$\rho =\frac{3(6.45\cdot 10^{24})}{4\pi (3.38\cdot 10^{10})^3}=3.99\cdot 10^{-8}\frac{kg}{m^3}$$