The meter is the length of the path travelled by light in vacuum during a time interval of 1/299 792 458 of a second. The kilogram is the unit of mass; it is equal to the mass of the international prototype of the kilogram.

SI System and Standard Unit of Length

SI System:

- SI system stands for the International System of Units.
- It is a system of measurement used worldwide.
- It is based on the metric system.
- It is also known as the metric system of measurement.

Standard Unit of Length:

- Length is a physical quantity that measures the distance between two points.
- It is measured in standard units of length.
- In SI system, the standard unit of length is the metre (m).
- One metre is defined as the distance travelled by light in a vacuum in 1/299,792,458 seconds.

Other Units of Length:

- In SI system, other units of length are derived from the metre.
- For example, the centimetre (cm) is 1/100th of a metre, and the kilometre (km) is 1000 metres.
- However, the metre is the standard unit of length, and it is used for scientific and technical purposes.

Importance of Standard Units:

- Standard units of measurement are important because they provide a common language for scientists and engineers to communicate their ideas and findings.
- They allow for accurate and precise measurements, which are essential in many fields, including physics, chemistry, engineering, and medicine.
- Standard units also help to ensure that measurements are consistent and comparable across different countries and industries.

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