Variable-mass system the momentum of the system varies for Therefore, by Newton's second law Noting that u - v is the velocity of d"m" relative to "m", symbolized as v, this final equation can be arranged as In a system where mass is being ejected or ablated from a main body, the derivation is slightly different. At time "t", let a mass "m" travel at a velocity v, meaning the initial momentum of the system is Since the main body will be losing mass, d"m" will be negative, meaning that at a time "t" + d"t" the momentum of the system becomes
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