Description: There is a particular point whose movement is simpler than that of the others. Study from the motion of a solid in the field of gravity (and whose center of inertia is not in the middle) by flash animation - For a small body, and for a uniform gravity field, the center of inertia and the center of mass are confused with the center of gravity.
Definition
Center of mass : We call center of mass (If the gravitational field is assumed to be uniform, here is also the center of gravity) of the material system S, the point G defined by
, with M ∈ S .