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Force of gravity

  1. Aug 13, 2009 #1
    does the following equation

    Fg = (G m1 Me)/Re^2

    the R is the radius had to get the e subscript

    neglect the fact that

    the Earth isn't really a sphere?

    that the Earth dosen't move in a complete circular orbit?

    That the Earth experiances a drag force among others as it moves through space?

    That the Earth spins and that it experiances a latitude-dependent centrifugal force?
  2. jcsd
  3. Aug 13, 2009 #2


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    Staff Emeritus
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    Gold Member

    Yes, to all of them. However only the first is of any significance. The others do not effect the force of gravity in any way. The last will effect the measured weight of a body but not the earths gravity.
  4. Aug 13, 2009 #3
    It also neglects the fact that the density of the earth is inconsistent. Perhaps the largest inconsistency in density is that continental crust has more silicon dioxide which is lighter and therefore floats higher on the semi-molten mantle, while oceanic crust is more dense, contains more magnesium and iron (which makes basalt black), so the oceanic crust floats lower on the mantle.
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