What defines a derived unit?

A derived unit is defined as a unit of measurement that is created by combining base units according to mathematical relationships. This means that derived units are calculated using one or more of the fundamental units, which include units such as meters, kilograms, seconds, and others. For example, speed is a derived unit that can be expressed as meters per second (m/s), which combines the base unit of distance (meters) with the base unit of time (seconds).

This method of defining derived units allows for a wide variety of measurements to be made that can describe complex physical quantities. The ability to express these complex relationships mathematically is essential in fields such as physics and engineering, where understanding how various quantities interact is necessary for calculations and predictions.

The other choices do not accurately characterize derived units. An absolute quantity refers to a value that is exact and not dependent on measurement, while units that involve neither distance nor time do not pertain specifically to derived units. A complex unit that cannot be simplified would be unrelated—a derived unit can often be simplified to make calculations easier, reflecting the interconnectedness of different physical concepts.