What is the diffrent between center of mass and center of gravity?
The centre of mass of a system of particles (or a continuous body) is the unique point at which the entire mass of the system (or body) may be considered to be concentrated. For many purposes the system behaves as though the mass were concentrated at the centre of mass. In a uniform gravitational field, the centre of gravity is located at precisely the same point as the centre of mass. So, in most everyday scenarios, the centre of gravity is the same as the centre of mass. If, however, a system is sufficiently large that the non-uniformity of the gravitational field experienced by the system becomes significant, then the centre of gravity will be slightly displaced from the centre of mass.
