Oscillating rigid rod in resistive-force theory
= Oscillating rigid rod in resistive-force theory
A rigid rod with moving centre and changing orientation has material <velocity> $\dot{\mathbf X}+s\dot\theta\mathbf n$. Its centred rotational <velocity> is odd in arclength and has no resultant <force>, while its orientation-dependent resistance tensor couples translation to transverse <force>. <Resistive-force theory> uses per-length coefficients $c_\parallel,c_\perp$.