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 causes it to move in direction of force without rotation. 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.