|
Title: how does gravity affect objects which are far beyond the surface of the earth? Post by: fjohn14 on Aug 1, 2013 Just need some help here.
Title: how does gravity affect objects which are far beyond the surface of the earth? Post by: mhughes2322 on Aug 1, 2013 Content hidden
Title: how does gravity affect objects which are far beyond the surface of the earth? Post by: bulgaria on Aug 1, 2013 The earth's pull on an object is inversely proportional to the square of the object's distance from the *center* of the earth.
Sitting here now, we are about 4,000 miles from the earth's center. The above "inverse square" law means that if we double that distance (so we're 8,000 miles from earth's center, or 4,000 miles above the surface), the earth's pull will diminish by 1/2², or 1/4. This means the earth's pull gets ever weaker with distance, but never entirely vanishes. For example, at the distance of the moon (about 60 earth radii), the pull of the earth is about 1/60², or 1/3600 as strong as it is here on the surface. That's still strong enough to keep the moon in tow. |