<Dl> <Dd> g (r) = − G M (r) r 2 . (\ displaystyle g (r) = - (\ frac (GM (r)) (r ^ (2))).) </Dd> </Dl> <Dd> g (r) = − G M (r) r 2 . (\ displaystyle g (r) = - (\ frac (GM (r)) (r ^ (2))).) </Dd> <P> where G is the gravitational constant and M (r) is the total mass enclosed within radius r . If the Earth had a constant density ρ, the mass would be M (r) = (4 / 3) πρr and the dependence of gravity on depth would be </P> <Dl> <Dd> g (r) = 4 π 3 G ρ r . (\ displaystyle g (r) = (\ frac (4 \ pi) (3)) G \ rho r .) </Dd> </Dl>

Acceleration due to gravity vs gravitational field strength