Given Newton's gravity formula, F=G*(M*m)/(r^2)F=GMmr2, what are the SI units of the universal gravity constant, GG?

1 Answer
Mar 19, 2016

GG has the SI units m^3/(kg*s^2)m3kgs2

Explanation:

FF is the force of gravity: (kg*m)/s^2kgms2

MM and mm are masses, in kgkg

rr is the distance between the masses, in mm (meters)

This gives

(kg*m)/s^2 = G xx (kg^2)/(m^2)kgms2=G×kg2m2

m^2*(kg*m)/s^2 = G xx kg^2m2kgms2=G×kg2
m^2*(kg*m)/s^2*1/k^2 = Gm2kgms21k2=G
m^2*(cancel(kg)*m)/s^2*1/k^cancel(2) = G
(m^3)/s^2*1/k = G
G = m^3/(kg*s^2)