# FAIRDO BG example 3.2.cellml

## Bond graph example: A mechanical system

Here we show a simple mechanical system with a spring for static energy storage (compliance C), a mass (L) for dynamic (inertial) energy storage, and a damper (R) for dissipating energy.
The potentials *u*^{m}_{C}, *u*^{m}_{R}, *u*^{m}_{L} (superscript ‘m’ for ‘mechanical’) are now the mechanical forces and the flow *v*^{m}_{1} is the velocity of the displacement *q*^{m}_{1}. i.e., *v*^{m}_{1} = (*dq*^{m}_{1}) ⁄ *dt*. There is one common point where energy is balanced (the 1:node) and in this system there is no need for a 0:node for mass conservation.

The **Views Available** menu to the right provides various options to explore this model here in the Physiome Model Repository.
Of particular interest is the *Launch with OpenCOR* menu item, which will load the simulation experiment shown below directly into the OpenCOR desktop application.