Final answer:
SI fundamental units are length, mass, time, and electric current. Derived units like newton and joule are combinations of these base units with special names, used for convenience in scientific measurements.
Step-by-step explanation:
The combination of SI fundamental units is the basis for describing physical quantities in science, particularly in Physics. The fundamental SI units according to the textbook in question are length, mass, time, and electric current, with all other physical quantities derived from these base units. For example, the unit 'newton' (N) is a derived SI unit for force and is a combination of mass (kilograms), length (meters), and time (seconds) equivalent to kg·m−s−.
Some specific combinations with special names help make working with these units easier. A newton, for instance, is the name given to the combination kg·m−s−, and a joule (J) is termed for kg·m²−s−, defining energy. These units facilitate communication and precision in scientific measurements. For context, speed is a derived unit measured as distance over time, exemplified by meters per second (m/s).
Derived units can involve complex combinations of the base units, and they often have special names for convenience. It is essential for scientific communication to recognize and correctly use these SI units and their derived forms.