Let a mechanical system be constructed from n rigid bodies, B i, i=1,...,n, and let the resultant of the applied forces on each body be the force-torque pairs, F i and T i, i = 1,..., n. Notice that these applied forces do not include the reaction forces where the bodies are connected. Finally, assume that the velocity V i and angular velocities ω i, i =1,..., n, for each rigid body, are defined by a single generalized coordinate q. Such a system of rigid bodies is said to have one degree of freedom.