Ignorable Coordinate

ignorable coordinate

[ig′nȯr·ə·bəl kō′ȯrd·ən·ət]
(mechanics)

Ignorable Coordinate

 

a generalized coordinate of a mechanical system that does not appear in the system’s Lagrangian function or other characteristic functions. The presence of ignorable coordinates simplifies the integration of the corresponding differential equations of motion of a mechanical system. For example, if the coordinate q1, does not appear in the Lagrangian function L, the Lagrange equation

takes the form

and immediately yields the integral