Axial and arclength travelling-wave speeds
= Axial and arclength travelling-wave speeds
{title2=$Q=V\Lambda/\lambda$}
For a periodic <inextensible filament> with arclength period $\Lambda$ and projected axial period $\lambda$, material points slide tangentially through the wave frame at speed $Q$. An axial pattern speed $V$ relative to mean filament motion gives $Q\lambda/\Lambda=V$. Confusing the two speeds changes the swimming-to-wave-speed ratio by $\lambda/\Lambda$.