Question

Distinguish between fundamental and derived units and give examples of derived units.

Answer 1

Difference between fundamental and derived units:

	Fundamental units	Derived units
1.	Fundamental units are all those units that do not depend on any other unit (including themselves).	These units are all those units that are obtained by multiplying and/or dividing one or more fundamental units with or without introducing any other numerical factor.
2.	These units cannot be further reduced to the elementary level; in fact, these are elementary units.	These units can be reduced to their elementary level, which is composed of fundamental units.
3.	These units cannot be expressed in terms of derived units.	Derived units can be expressed in terms of fundamental units.
4.	Only seven fundamental units exist in Metric System or SI system.	There exist a large number of derived units in the Metric System.
5.	Examples: Length (meter, m) Mass (kilogram, kg) Time (second, s) Temperature (kelvin, K) Amount of substance (mole, mole) Electric current (ampere, A) Luminous intensity (candela, cd)	Examples: Velocity (m/s) Acceleration (m/s2) Momentum (kg-m/s) Force (N) Density (kg/m3) Heat (J) Energy (J) Power (W), etc.