## Double pendulum using heavy spring

January 18, 2015 compiled on — Wednesday July 06, 2016 at 08:36 AM

This Demonstration describes the dynamics of a pendulum made up of two springs. The top spring
mass is taken into account in the dynamics using Raleigh's method while the lower spring is assumed to
be massless.
The pendulum bob slides back and forth; it is attached to the end of the lower massless spring. The bob
has three degrees of freedom. The equations of motion for the bob and the pendulum are derived using the
Lagrangian method and Mathematica's built-in function NDSolve is used to obtain a numerical solution.