This Demonstration shows the motion of a quadruple pendulum, consisting of four point masses connected by massless rods. In common with the double and triple pendulum, the quadruple pendulum can exhibit chaotic behavior. After you change a control, click the "reset" button to see the effect.
The equations of motion for each mass in the quadruple pendulum system are second-order differential equations derived from the Euler–Lagrange equation. These second-order differential equations are solved via Mathematica's NDSolve function.
In this system, the potential energy of each of the masses increases with its height. The total potential and kinetic energies, along with the conserved total energy, are shown in the graphic.