Variable-mass system events. The following derivation is for a body that is gaining mass (accretion). A body of time-varying mass "m" moves at a velocity v at an initial time "t". In the same instant, a particle of mass dm moves with velocity u. The initial momentum can be written as Now at a time "t" + d"t", let both the main body and the particle accrete into a body of velocity v + dv. Thus the new momentum of the system can be written as Since d"m"dv is the product of two small values, it can be ignored, meaning during d"t"
Canon of the Mass in all liturgical texts. Fortescue remarked that the medieval explanations are interesting as showing with what reverence people studied the text of the Canon and how, when every one had forgotten the original reasons for its forms, they still kept the conviction that the Mass is full of venerable mysteries and that all its clauses mean more than common expressions. He added that in this conviction the sometimes naive medieval interpreters were eminently right. Canon of the Mass Canon of the Mass (Latin: "Canon Missæ", "Canon Actionis") is the name given in the Roman Missal, from the first typical edition