Mass Matrix

In analytical mechanics, the mass matrix is a symmetric matrix that expresses the relationship between the time derivative of a system's generalized coordinate vector and the system's kinetic energy, playing the same role for a whole system of coupled generalized coordinates that an ordinary particle's scalar mass plays in the familiar formula for its kinetic energy in terms of its velocity. The mass matrix can be derived from that same particle formula by expressing each particle's position in terms of the generalized coordinates, and in general it depends on the system's own state and so can vary with time; it appears as one term of the coupled differential equations that Lagrangian mechanics produces to describe how a system evolves. This description is adapted from Wikipedia contributors under CC BY-SA 4.0; changes were made. https://creativecommons.org/licenses/by-sa/4.0/