The physical quantities which are independent or neutral that is, they do not depend on other quantity, rather other quantities depend on them, are called fundamental quantities.
What is fundamental quantity?
In physics and other sciences, a fundamental quantity is a physical property that can’t be expressed in terms of any other physical quantities. It’s like a building block, serving as the basis for defining and measuring all other physical quantities.
Think of it this way: if you imagine all physical quantities as a giant family tree, the fundamental quantities are the roots. They stand alone, independent of each other, yet they support and give rise to all the other branches, which represent derived quantities.
Some key characteristics of fundamental quantities
- Independent: They cannot be defined or derived from any other physical quantities.
- Basic: They are the simplest and most elementary physical properties we can measure.
- Defined by convention: We choose specific standards and units to represent them, like the meter for length and the kilogram for mass.
- Limited number: Depending on the chosen system of units, there are a specific number of fundamental quantities. In the International System of Units (SI), the current set includes seven:
- Length: Measured in meters (m)
- Mass: Measured in kilograms (kg)
- Time: Measured in seconds (s)
- Electric current: Measured in amperes (A)
- Thermodynamic temperature: Measured in kelvins (K)
- Amount of substance: Measured in moles (mol)
- Luminous intensity: Measured in candelas (cd)
Why is the reason to understanding fundamental quantities?
Understanding fundamental quantities is crucial for several reasons
Consistency: They provide a universal and consistent foundation for comparing and measuring physical phenomena across different fields.
Derivation: They allow us to express all other physical quantities in terms of combinations of themselves and their units. This opens up the possibility of deriving and understanding various relationships and laws in physics.
Clarity: They simplify complex physical concepts by breaking them down into their basic building blocks.
