Motion of Centre of Mass Physics

Study Notes

The centre of mass of a system of particles moves according to the equation: MA = F_ext, where M is the total mass of the system, A is the acceleration of the centre of mass, and F_ext is the sum of all external forces acting on the particles.
This equation states that the centre of mass of a system of particles moves as if all the mass of the system was concentrated at the centre of mass and all the external forces were applied at that point.
To determine the motion of the centre of mass, no knowledge of internal forces of the system of particles is required; only the external forces need to be known.
The equation MA = F_ext is applicable to any system of particles, regardless of the nature of the system or the motion of its individual particles.
The centre of mass moves according to the equation MA = F_ext, whether the system is a collection of particles with internal motions, or a rigid body with translational and/or rotational motion.
In earlier studies, extended bodies were treated as single particles, but now we can treat them as systems of particles and obtain the translational component of their motion by assuming the mass of the whole system is concentrated at the centre of mass and all external forces act at the centre of mass.
The centre of mass moves according to the equation MA = F_ext, which implies that the total mass of a system of particles times the acceleration of its centre of mass is the vector sum of all the forces acting on the system of particles.