Units that require more than one measurement and cannot be measured in base units are known as what?

Units that require more than one measurement and cannot be measured in base units are classified as derived units. Derived units are formed by the combination of base units to express a physical quantity. For example, velocity is a derived unit that combines the base units of distance (meters) and time (seconds) to create meters per second (m/s).

Derived units are essential in physics and engineering because many physical phenomena cannot be described adequately using base units alone. They allow for a more comprehensive representation of complex measurements, such as force (newtons), pressure (pascals), and energy (joules), which all rely on the combination of base units to convey meaningful information.

In contrast, base units represent the fundamental quantities in a measurement system, such as length, mass, and time, and do not combine multiple measurements. Imperial units and standard units generally refer to specific measurement systems but do not define the concept of units requiring combinations of measurements.