Kokonaismassa

Kokonaismassa is a general term used in Finnish-language scientific writing to denote the total mass of a system. It represents the sum of the masses of all constituents, including any components that contribute to the system's inertia and gravitational field. In mathematical form, for a discrete set of objects M_tot = Σ_i m_i; for a continuous medium, M_tot = ∫ ρ(x) dV, where ρ is the mass density.

The interpretation of kokonaismassa varies by context. In laboratory and engineering contexts it may refer to the gross or complete mass, including packaging or mounting hardware, whereas in physics discussions it usually refers to the mass of the system's material substance, excluding external supports. In some astronomical contexts it denotes the total gravitational mass inferred from dynamics, which can include dark matter and other non-luminous components.

Applications and calculation: Kokonaismassa is used to compute the gravitational parameter μ = G M_tot, to determine orbital periods via Kepler's laws, to assess structural loads, and to derive inertia. Measurement: On small scales, mass is measured with scales or balances; on large scales, mass is inferred from dynamics, rotation curves, velocity dispersion, or gravitational lensing; in astronomy, mass models integrate density distributions.

See also: Mass, Net mass, Gross mass, Mass distribution, Gravitational parameter.