Now, what if I move outside this sphere? It turns out that the gravitational field due to a spherical distribution produces the same gravitational field as if all the mass was concentrated into a single point at the center of the sphere. This is kind of nice, as it allows us to easily calculate the gravitational field from the Earth by just using the distance from the center of the object, instead of worrying about its actual size and its total mass.
Now, we have one more thing to consider: How does the gravitational field (and therefore your weight) change as you get closer to the center of the Earth?
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