Re: Why do books give gravity to 2 sig figs? -9.8 m/s2

The acceleration due to earth's gravity is usually given as 9.80 m per 
second per second because it is very close to that value!!!  You can find, 
though, charts (maybe on the Internet?) which give the measured values of g at 
various locations around the world.  The differences are due to differing 
densities of the underlying crust and also due to the fact that the earth is 
not perfectly spherical.  There are also differences based on latitude due to 
the centripetal force of our motion of the earth's rotation on its axis.  I 
could not find Greenville, SC, listed, but I did find the following locations 
in the chart I have:


  Location         g

  Atlanta          9.79527

  Charleston SC    9.79549

  Durham NC        9.79838

  Ithaca NY        9.80303

  Key West FL      9.78973




John Link

  MadSci Physicist