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
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