Question

defination of motion of centre of mass​

Answer 1

Answer:

The center-of-mass (COM) is the single point on a structure which characterizes the motion of the object if the object shrinks to a point mass.

Answer 2

The center-of-mass (COM) is the single point on a structure which characterizes the motion of the object if the object shrinks to a point mass. If a net force is applied to the COM the resulting motion will be translation (the object will not rotate).