Instability of the Maxwell’s Pendulum Motion

The article deals with the problem of the vertical position stability of the Maxwell’s pendulum performing the periodic upward and downward movements. It is shown that for any values of the pendulum parameters, its vertical position is unstable in the sense that in the system there are oscillations of the thread about the vertical of final amplitude for arbitrarily small initial deviations. In addition, it has been found that no impact phenomena occur when the Maxwell’s pendulum moves and the model of this pendulum is incorrect in the sense of Hadamard when using the parameters frequently adopted in the literature.