Chapter 12: Theorem of momentum D812-1 The center of mass of a system of particles, external forces and internal forces 四§12-2 Momentum and impulse D$12-3 Theorem of momentum 四§12-4 Theorem of motion of the center of mass7 §12–1 The center of mass of a system of particles, external forces and internal forces §12–2 Momentum and impulse §12–3 Theorem of momentum §12–4 Theorem of motion of the center of mass Chapter 12: Theorem of momentum