“…However, an interest in the investigation of various aspects of the dynamical behavior of pendulum systems is mostly caused by the fact that many effects and phenomena first discovered in pendulum systems were later established for much more complicated physical systems such as rings, shells, plates, and various media in cylindrical and spherical cavities. Moreover, various pendulum systems were successfully used for the approximate mathematical simulation of the dynamics of the indicated complicated oscillating systems [6][7][8][9][10][11]. Sometimes, despite the considerable simplification, the obtained differential equations of motion fairly exactly describe the dynamics of these complicated oscillating systems.…”