Center of mass rigid body, the gravity forces will not cause the body to rotate, which means the weight of the body can be considered to be concentrated at the center of mass. The linear and angular momentum of a collection of particles can be simplified by measuring the position and velocity of the particles relative to the center of mass. Let the system of particles "P", "i"=1...,"n" of masses "m" be located at the coordinates r with velocities v. Select a reference point R and compute the relative position and velocity vectors, The total linear and angular momentum vectors relative to the
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