<P> In physics , the center of mass of a distribution of mass in space is the unique point where the weighted relative position of the distributed mass sums to zero , or the point where if a force is applied it moves in the direction of the force without rotating . The distribution of mass is balanced around the center of mass and the average of the weighted position coordinates of the distributed mass defines its coordinates . Calculations in mechanics are often simplified when formulated with respect to the center of mass . It is a hypothetical point where entire mass of an object may be assumed to be concentrated to visualise its motion . In other words , the center of mass is the particle equivalent of a given object for application of Newton 's laws of motion . </P>
where is the center of mass of an object
the unique point where the weighted relative position of the distributed mass sums to zero