Derivation of the Navier–Stokes equations equation), three important concepts may be concisely written: conservation of mass, conservation of momentum, and conservation of energy. Validity is retained if formula_5 is a vector, in which case the vector-vector product in the second term will be a dyad. A general momentum equation is obtained when the conservation relation is applied to momentum. If the intensive property formula_5; considered is the mass flux (also "momentum density"), i.e. the product of mass density and flow velocity formula_17, by substitution in the general continuum equation: where formula_19 is a dyad, a special case of tensor product, which results in a second
Body of Christ says: "The body of Christ", indicating what is held to be the reality of what is given. Since the consecrated bread is believed to be the body of Christ and sacred, what remains of the host after celebration of Mass is kept in the church tabernacle. This is primarily for the purpose of taking Communion to the sick, but also to serve as a focal point for private devotion and prayer. On appropriate occasions, there may be public Eucharistic adoration. The Eastern Orthodox Church also believes that the Eucharistic elements of bread and wine become the actual body and blood