Question

Suppose that you are on a planet, that has an average radius 1*10^9 meters and average density 7.4 kg/m^3. Assuming that it is a perfect sphere, find the mass of the planet.

Answer 1

30.997 x 10^27 kg :)

Answer 2

Thats the volume right?

Answer 3

Mass of planet is Density x Volume.
Density is given as 7.4kg/m^3
Volume of a Sphere is 4/3πr^3
since radius is given as 1x10^9 then we know the volume is 4/3π x (10^9)^3
so then the mass must be that times the density.
which is then 7.4 x 4/3 x π x (10^9)^3
which is 30.997 x (10^9)^3 = 30.997 x 10^27

Answer 4

Makes PLENTY of sense now