# Last limit of earth's gravity

#### aliashar86

Joined Nov 23, 2006
71
can anyone plz tell wt's the last limit of eath's gravity.
i have got information that is has also reached "negative value".
i) does the value of "g" with negative sign possible.

ii) does value of "g" can increase or decrease at the surface of earth.

i have gone through "variation of g, but there i didn't get any word where it gives information that the value of "g" can be negative.

#### Papabravo

Joined Feb 24, 2006
19,612
can anyone plz tell wt's the last limit of eath's gravity.
i have got information that is has also reached "negative value".
i) does the value of "g" with negative sign possible.

ii) does value of "g" can increase or decrease at the surface of earth.

i have gone through "variation of g, but there i didn't get any word where it gives information that the value of "g" can be negative.
The force of Earth's gravity extends to infinity. There is no practical limit to it effect. This is the equation for the force between two masses m1, and m2 separated by a distance r.

Rich (BB code):
F = G *( (m1*m2) / r^2)
G is a positive constant. Since each element in the equation is positive the result must be positive.

Small "g" refering to the acceleration of gravity at the surface of the Earth is approximately 9.8 m/sec/sec. It cannot be negative. It can approach zero at very large distances. As you climb a mountain or descend into a valley the value of "g" will change according to the formula above and Newton's Second Law.

A negative value for g would imply that gravity pushes things apart which it demonstrably does not do.

#### jjimenez01

Joined Dec 8, 2006
14
Acceleration due to gravity "g" is infact a positive number. The only types of negative accelerations that you will find would be when a body is de-decelerating. For example, a car applying on the brakes would experience a de-celeration, or a negative acceleration.