the mass is divided into 40 parts.
the mass is divided into 40 parts.
the mass is divided into how many parts?
40
Na
Na
for things and systems made up of many parts, like an atomic nucleus, planet, or star, the relativistic mass is the sum of the relativistic masses (or energies) of the parts, because energies are additive in isolated systems. this is not true in open systems, however, if energy is subtracted. for example, if a system is "bound" by attractive forces, and the energy gained due to the forces of attraction in excess of the work done is removed from the system, then mass is lost with this removed energy. for example, the mass of an atomic nucleus is less than the total mass of the protons and neutrons that make it up, but this is only true after this energy from binding has been removed in the form of a gamma ray (which in this system, carries away the mass of the energy of binding). this mass decrease is also equivalent to the energy required to break up the nucleus into individual protons and neutrons (in this case, work and mass would need to be supplied). similarly, the mass of the solar system is slightly less than the sum of the individual masses of the sun and planets.
mass–energy equivalence