H Bar Serving $\pi$

Once there was a deliveryman
who went in a circle
and made delivery twice
that is how H Bar
got her two pies

$h=2\pi x.mv$

$\hbar=\cfrac{h}{2\pi}=x.mv$

More importantly, $h$, $\hbar$ is dependent on $x$ and $v$.  In the case when $v=c$, at light speed, then $h$, $\hbar$ is dependent only on $x$.