This lecture covers the concept of central motion, focusing on the moment of a force with respect to a point O, the kinetic moment of a material point with respect to O, and the properties of central motion. It also discusses the formula of Binet, the theorem of kinetic moment, and the velocity in a plane. The historical approach of Tycho-Brahe, Kepler, and Newton is contrasted with the modern approach, showing how the elliptical trajectories of planets can be derived from the force's 1/r² dependence. The lecture also explores the laws of Kepler, conservation of energy, and the effective potential in central motion.