The
center of gravity of an object is a
theoretical point which identifies its effective location. It is roughly the three-dimensional average of the positions of all
protons and neutrons in the object.
An easier way to
identify the location of the center of gravity is by
suspending a non-central part of the object in place, while allowing it to spin sufficiently on any
axis. Once it
comes to rest, the center of gravity lies along the line containing the suspended point and with the direction of the gravitational
force vector. By performing this process from two or more points of suspension, the center of gravity can be isolated as a point.
In many physical
calculations, the center of gravity can be used to represent the
position of the entire object, so long as the object's spin, etc. are not concerned.
If the object has a simple
geometric shape, with its mass evenly distributed (unweighted dice, a baseball), the center of gravity will lie at the
geometric center of the object.