Since we are using a force-wave simulation, the state variable
(delay element output) is in units of physical force (newtons).
Specifically,
. (The physical force is, of
course, 0, while its traveling-wave components are not 0 unless the
mass is at rest.) Using the fundamental relations relating traveling
force and velocity waves
where
here, it is easy to convert the state variable
to
other physical units, as we now demonstrate.
The velocity of the mass, for example, is given by
Thus, the state variable
The kinetic energy of the mass is given by
I.e., the square of the state variable