ZdzisĹ‚aw Pluta, Tadeusz Hryniewicz, Adequate Theory of Vertical Motion of a Mass-Elastic System, Volume 11, International Letters of Chemistry, Physics and Astronomy (Volume 11) https://www.scipress.com/ILCPA.11.116 Abstract: The paper covers an adequate theory on vertical motion of the mass-elastic system. This system is an oscillator with the motion being a free harmonic motion. The first extended link of the consideration presents a critical analysis of the existent knowledge referred to this subject. Then the energetic states of the oscillator have been determined. Next the force characteristics of the free harmonic motion of the oscillator are presented. A general source equation of the path/way length and the resulting detailed forms, signalizing extensive possibilities to build up the characteristics, have been presented. Finally the connections between the characteristics of real and simulative motions were derived. It should be added that this first mentioned motion is the subject of adequate description presented here. The simulated motion is referred to the existent classical theory which has been subjected under a critical consideration. Keywords: Equation of Path/Way Length, Force Characteristics, Potential Field, Ree Harmonic Oscillator Motion, Theory of Oscillation Motion, Time Constant, Vertical Mass-Elastic System