When it comes to understanding the fundamental units of measurement, it is important to have a clear understanding of what these units are and how they are used in various fields of science and everyday life. In this article, we will explore the concept of fundamental units and discuss which of the following is not considered a fundamental unit: kilogram, meter, second, or newton.

## Understanding Fundamental Units

Fundamental units, also known as base units, are the basic building blocks of measurement. They are the units from which all other units are derived. These units are chosen based on their relevance and importance in the physical world. The International System of Units (SI) is the most widely used system of measurement, and it defines seven fundamental units.

### The Seven Fundamental Units

The seven fundamental units defined by the SI are:

**Meter (m):**The meter is the fundamental unit of length. It is defined as the distance traveled by light in a vacuum in 1/299,792,458 of a second.**Kilogram (kg):**The kilogram is the fundamental unit of mass. It is defined as the mass of the International Prototype of the Kilogram, a platinum-iridium cylinder kept at the International Bureau of Weights and Measures in France.**Second (s):**The second is the fundamental unit of time. It is defined as the duration of 9,192,631,770 periods of the radiation corresponding to the transition between two hyperfine levels of the ground state of the cesium-133 atom.**Ampere (A):**The ampere is the fundamental unit of electric current. It is defined as the constant current that, if maintained in two straight parallel conductors of infinite length and negligible circular cross-section, placed one meter apart in a vacuum, would produce between these conductors a force equal to 2 × 10^−7 newtons per meter of length.**Kelvin (K):**The kelvin is the fundamental unit of temperature. It is defined as 1/273.16 of the thermodynamic temperature of the triple point of water.**Mole (mol):**The mole is the fundamental unit of amount of substance. It is defined as the amount of substance that contains as many elementary entities as there are atoms in 0.012 kilograms of carbon-12.**Candela (cd):**The candela is the fundamental unit of luminous intensity. It is defined as the luminous intensity, in a given direction, of a source that emits monochromatic radiation of frequency 540 × 10^12 hertz and that has a radiant intensity in that direction of 1/683 watt per steradian.

## Which of the Following is Not a Fundamental Unit?

Now that we have a clear understanding of the seven fundamental units, we can determine which of the following is not considered a fundamental unit: kilogram, meter, second, or newton. The answer is **newton**.

### The Newton and Its Role

The newton (N) is not a fundamental unit but rather a derived unit. It is the unit of force in the SI system and is defined as the force required to accelerate a one-kilogram mass by one meter per second squared. In other words, it is the force required to cause a mass of one kilogram to accelerate at a rate of one meter per second squared.

The newton is derived from the fundamental units of kilogram, meter, and second. It is calculated using the formula:

F = m × a

Where:

**F**is the force in newtons**m**is the mass in kilograms**a**is the acceleration in meters per second squared

By multiplying the mass and acceleration, we can determine the force in newtons. This shows that the newton is not a fundamental unit but rather a derived unit based on the fundamental units of mass, length, and time.

## Conclusion

In conclusion, the newton is not a fundamental unit but rather a derived unit of force. The fundamental units are the meter, kilogram, second, ampere, kelvin, mole, and candela. These units form the foundation of measurement and are used in various scientific and everyday applications. Understanding the distinction between fundamental and derived units is crucial for accurate and consistent measurement across different fields of study.

## Q&A

### 1. What are fundamental units?

Fundamental units, also known as base units, are the basic building blocks of measurement. They are the units from which all other units are derived. The International System of Units (SI) defines seven fundamental units: meter, kilogram, second, ampere, kelvin, mole, and candela.

### 2. What is the difference between fundamental and derived units?

Fundamental units are the basic units of measurement, while derived units are derived from fundamental units through mathematical combinations. Derived units are used to measure quantities that are derived from the fundamental units, such as force, velocity, and energy.

### 3. Why is the newton not a fundamental unit?

The newton is not a fundamental unit because it is derived from the fundamental units of mass, length, and time. It is the unit of force in the SI system and is defined as the force required to accelerate a one-kilogram mass by one meter per second squared.

### 4. What is the formula to calculate force in newtons?

The formula to calculate force in newtons is F = m × a, where F is the force in newtons, m is the mass in kilograms, and a is the acceleration in meters per second squared.

### 5. Can derived units be converted into fundamental units?

Yes, derived units can be converted into fundamental units by using the appropriate conversion factors. For example, the derived unit of energy, the joule, can be converted into fundamental units by using the conversion factor 1 J = 1 kg·m^2/s^2.