Sekundärgrößen

Sekundärgrößen, also known as derived quantities, are physical quantities whose definitions are based on one or more fundamental physical quantities. In contrast to fundamental quantities, which are defined independently, secondary quantities are expressed as mathematical combinations of fundamental quantities. The International System of Units (SI) defines seven fundamental quantities: length, mass, time, electric current, thermodynamic temperature, amount of substance, and luminous intensity. All other units within the SI system are derived from these.

For example, area is a secondary quantity derived from length. Its unit, the square meter (m²), is obtained by multiplying length by length (m × m). Velocity is another secondary quantity, defined as the rate of change of displacement with respect to time. Its SI unit, meters per second (m/s), is derived from the fundamental units of length and time. Similarly, force is a secondary quantity defined by Newton's second law (F = ma) as the product of mass and acceleration. Its SI unit, the newton (N), is equivalent to kg⋅m/s².

The concept of secondary quantities is crucial for organizing and understanding physical laws and measurements. By expressing complex quantities in terms of simpler, fundamental ones, scientists can establish consistent relationships and ensure dimensional homogeneity in equations. This systematic approach allows for the development of coherent theoretical frameworks and facilitates accurate experimental analysis across various scientific disciplines. The SI system's structure, based on fundamental and derived units, provides a standardized foundation for global scientific communication and technological advancement.