...Firdaus E. Udwadia; Nami Mogharabin This paper develops an alternative description of the general equation of motion for constrained mechanical systems with singular mass matrices. The formulation gives a new explicit equation of motion for such systems and provides a simple and elegant way...

...Firdaus E. Udwadia; Nami Mogharabin Zero-mass particles are, as a rule, never used in analytical dynamics, because they lead to singular mass matrices. However, recent advances in the development of the explicit equations of motion of constrained mechanical systems with singular mass matrices...