Difference between derived and fundamental quantity
Derived quantities are physical quantities that are obtained from combinations of fundamental quantities. They cannot be directly measured, but are calculated or derived from fundamental quantities. Examples of derived quantities include velocity (which is derived from the fundamental quantities of length and time) and acceleration (which is derived from the fundamental quantities of length and time).
Fundamental quantities, on the other hand, are independent and cannot be derived from any other physical quantities. They are the basic building blocks upon which all other physical quantities are based. Examples of fundamental quantities include length, time, mass, electric current, temperature, luminous intensity, and amount of substance.
In summary, derived quantities are obtained from combinations of fundamental quantities, while fundamental quantities are the basic units upon which all other physical quantities are based.