What does KT really mean??

[Steve A]

quote:

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Originally posted by Kimball:
[b] The formula to which you refer is

F=G*M1*M2/R^2

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If anyone really cares, this formula is not applicable to all cases.

This formula assumes that the masses are point sources and is usually good enought to use in the real world. With spherical bodies, such as planets, it is an exact solution and force changes in proportion to 1/r^2, as long as the the masses do not intersect. Once M1 goes below the surface of M2, the force changes proportional to r (i.e. it decreases).

The result is that for someone standing on the surface of a sphere, gravitational force is maximized. The force decreases as you move away (1/r^2), and the force decreases as you go deeper ( r). At the center of the earth, you would experience 0 gravitational force.

There are also higher order effects since real planets are not perfectly spherical nor completely solid. These cause tides and precession of satellite orbits.

That geeky enough for you?

Steve