ON THE USE OF QUASI-VELOCITIES IN IMPULSIVE MOTION

The differential variational principle of Jourdain (JVP) is extended t o cover the dynamics of impulsive motion, formulated in terms of quasi -velocities, instead of time rates of change of true or Lagrangian gen eralized coordinates. This enlarges the scope of the JVP, because the extension of its range to encompass the use of quasi-velocities (which includes true velocities as a special case), enables the analyst to s olve a wider range of problems. It should be pointed out that the math ematical foundation of the JVP, which is based on the assumption that the variation of the position vectors as well as the time is zero (in true Lagrangian as well as quasi-coordinates), is ideally suited to th e physics of impulsive motion, where finite changes in the velocity ar e accompanied by negilgible changes in configuration and time.