Mass (say) 1 kilogram. Then we can measure the mass of any other object in the universe by colliding it with the reference object and measuring the accelerations. Additionally, mass relates a body's momentum p to its linear velocity v: and the body's kinetic energy "K" to its velocity: The primary difficulty with Mach's definition of mass is that it fails to take into account the potential energy (or binding energy) needed to bring two masses sufficiently close to one another to perform the measurement of mass. This is most vividly demonstrated by comparing the mass of the proton in the
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