Gravitational Potential-
In a gravitational field potential V at a point, P is defined as negative of work done per unit mass in changing the position of a test mass from some reference point to the given point.
Note-usually reference point is taken as infinity and potential at infinity is taken as Zero.
and it is given as
where
Gravitational potential
Field Intensity
small distance
We can also write
This means a negative gradient of potential gives the intensity of the field.
The negative sign indicates that in the direction of intensity the potential decreases.
It is a scalar quantity.
Gravitational Potential at a distance 'r'
If the field is produced by a point mass then
So
at