Reference problem ===================== Geometry --------- The system diagram is shown in the following figure: .. image:: images/10003C68000069D500005B2800C1BDD7955DD14B.svg :width: 298 :height: 254 .. _RefImage_10003C68000069D500005B2800C1BDD7955DD14B.svg: Material properties ---------------------- The properties of the material are as follows: stiffness :math:`K\mathrm{:}4{\pi }^{2}N\mathrm{/}m` Mass :math:`M\mathrm{:}100\mathit{kg}` amortization :math:`C\mathrm{=}0.4\pi \mathit{Ns}\mathrm{/}m` Boundary conditions and loads ------------------------------------- The spring is embedded at one end and subjected to a :math:`F` force at the free end. The point mass can only move in the direction :math:`x`. Initial conditions -------------------- At the initial moment, the mass is immobile and is in its equilibrium position. :math:`x(0)\mathrm{=}0m` :math:`v(0)\mathrm{=}0m\mathrm{/}s`