On the Velocity-gradient Dependence of the Kinetic Energy of a Continuum

The kinetic energy of a continuum is found to contain a term dependent on the velocity gradient when the material is assumed to be composed of elements which the variation of the velocity is taken into account. When this term is included in the equations pertaining to elastic wave propagation, cut-off frequencies are found for both irrotational and equivoluminal waves. (Author).