SI Base Units
Learning Objectives
- Students will be able to identify the seven SI base units and their symbols
- Students will understand what each base unit measures
- Students will understand the definitions and history of base units
Core Concepts
- Length: meter (m)
- Mass: kilogram (kg)
- Time: second (s)
- Electric current: ampere (A)
- Temperature: kelvin (K)
- Amount of substance: mole (mol)
- Luminous intensity: candela (cd)
Units
| meter | m |
| kilogram | kg |
| second | s |
| ampere | A |
| kelvin | K |
| mole | mol |
| candela | cd |
Interesting Fact
The kilogram was the last base unit to be redefined using a fundamental constant (2019)
Key Scientist
François Arago
Helped establish the meter as the international standard for length
Philosophy
The choice of base units reflects deep philosophical choices about what we consider fundamental in nature and how we decompose complex phenomena.
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