A hypothetical analogue of a disk galaxy is considered - a flat, extremely thin disk, inside of which there is a body, an analogue of a star. The density distribution function of the disk is specified, from which the forces acting on the body are calculated depending on its distance from the center of the disk. Based on the calculated forces, the so-called rotation curve was constructed. By adjusting the disk density function, without involving external forces, it was possible to ensure that the disk rotation curve became close in shape to the rotation curve of the real Milky Way galaxy. A hypothetical analogue of a disk galaxy is considered - a flat, extremely thin disk, inside which there is a some body, an analogue of a star. The density distribution function of the disk is given, according to which the forces acting on the body are calculated depending on its distance from the center of the disk. The calculated forces are used to construct the so-called rotation curve.