I read this background article the other day: fundamental quantity vs derived quantity In the language of measurement, quantities are quantifiable aspects of the world, such as time, distance, velocity, mass, temperature, energy, and weight, and units are used to describe their measure. Many of these quantities are related to each other by various physical laws, and as a result the units of some of the quantities can be expressed as products (or ratios) of powers of other units (e.g., momentum is mass times velocity and velocity is measured in distance divided by time). Those quantities whose units are expressed in terms of other units are regarded as derived quantities. Those that cannot be so expressed in terms of other units are regarded as "fundamental" quantities. I am facing a new situation today: Mark has an assignment to figure out which measurements in every day life are derived quantities vs fundamental quantities. Some of the examples he has include measuring the speed of something and simply what time it is. Using the knowledge I acquired from the background article, how should I answer correctly the following question regarding my new situation: Given a quantity of speed, will this be considered a fundamental quantity or a derived quantity?
Answer:
derived