Gladly, Tony. It's the solution to Newton's Universal Law of Gravitation for the attraction of two bodies:
F=Gm
1m
2/r
2 where G=Newton's Gravitational Constant, m
1 and m
2 are the masses of the two bodies, and r is the distance between them. To derive g, the acceleration of a body in a vacuum near the earth's surface,
g=F/m
b=Gm
e m
b/r
2m
b = Gm
e/r
2
where m
e= the mass of the Earth, and r=the radius of the Earth.
Note that the mass of the body drops out of the equation, so that all objects fall towards the earth at the same acceleration. But from the original Newton's law, the force exerted between the Earth and a body is proportionate to the body's mass. Kind of takes you back to high school, doesn't it?
But back to the
statics. When I stand on the earth, the earth is pushing on me just as hard as I'm pushing on the earth. That means that net force=0.
Which means I don't move. Which means I don't accelerate.
You remind me of a kid I used to help out in high school physics. He could never "get it", so he became a music producer and wound up as a millionaire.