Four astronauts are in a spherical space station. (a) if, as is typical, each of them breathes about 500 cm
of air with each breath, approximately what volume of air (in cubic meters) do these astronauts breathe in a year? (b) what would the diameter (in meters) of the space station have to be to contain all this air?

A) if each astronaut breathes about 500 cm³, the total volume of air breathed in a year is 14716.8m³.

B) The Diameter of this spherical space station should be 30.4m

Explanation:

The breathing frequency (according to Rochester encyclopedia) is about 12-16 breath per minute. if we take the mean value (14 breath per minute), we can estimate the total breaths of a person along a year:

If we multiply this for the number of people in the station and the volume each breath needs, we obtain the volume breathed in a year.

The volume of a sphere is:

So the diameter is:

electric field is a function of 1/r^2

yes, the force per unit charge for a point charge is inverse square law.