March 13, 2003
A: FROM MENTOR JOAN LUSK IN RI
the gravitational force between any two objects is inversely
proportional to the square of the distance between them : to 1/r^2
(one divided by r-squared) where r is the distance between their
centers. As r gets bigger and bigger the force gets smaller, but it
doesn't literally reach zero until r is infinite. But if you ask at
what distance from the earth does gravity become 1/100 of what it is
here at the surface, you can easily see that out in space 10 times as
far from the center (9 more earth's-radii away than the surface),
gravity will be down to 1/100 as much. And for any desired fraction
of the gravity at the surface you can find the corresponding distance.

Gravity acts at tremendous distances - influencing the motion of
galaxies all throughout the cosmos.
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A: FROM MENTOR DIANA DIONISIO IN CA
Gravity is due to the earths force and I'm not sure exactly what distance the earth's pull has no effect on a person's body. The force just gets smaller as a person or any object moves further from the center of the earth.
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A: FROM MENTOR SHEILA ENGLAND IN PA
Check out this web site:
http://newton.dep.anl.gov/askasci/wea00/wea00080.htm