Zdzisław Pluta, Tadeusz Hryniewicz, Critics of Existent Theory of Mathematical Pendulum, Part 1, ILCPA Volume 13, International Letters of Chemistry, Physics and Astronomy (Volume 13)
    In the framework of this paper a deep critics of existent theory of the simple mathematical pendulum is presented. This work consists of two parts. In the first part of the paper, a thesis is stated to derive a mystification character of the theory. The up-to-date, excerpted from the literature, descriptions of the oscillation motion of the mathematical pendulum, are delivered. This part of the paper is to show that the existent theory describes simply a shadow of the rotating apparent mathematical pendulum. The necessity to re-build the existent theory has been indicated.
    Amplitude, Angular Velocity, Force of Gravity, Force of Inertia, Mathematical Pendulum, Vibration Period