The book presents questions, mechanics of relative motion, invariably found in the theory and practice of complex machines, ships and aircraft, rockets and spacecraft, the movement of bodies relative to the Earth and in the explanation of natural phenomena. A strict distinction is made between the forces of physics (Newton), which create an acceleration relative to the coordinate system (non-rotating, with the beginning in the center of mass of the solar system) from the dalamber inertia forces and the Eulerian inertia forces, due to the choice of a mobile coordinate system .. Along with the presentation of the initial positions of classical mechanics, examples of the compilation of equations and the analysis of solutions to the problems of the dynamics of relative motion of various difficulties with a large number of explanatory figures are given. The book is intended for a wide range of readers - teachers of mechanics and its applications, engineers, researchers, as well as graduate students and senior students .