Units and Standards
1. Units and Standards
There are 4 fundamental scientific measurements: Mass, Length, Time, and Electric Charge
The following table summarizes their basic SI (International Metric System) units
| Fundamental Quantity | Mass |
Length, distance, displacement |
Time | Charge |
| SI Unit | kg (kilogram) | m (metre) | s (second) | C (coulomb) |
| Symbol | m | Δd | t | Q |
2. Scalar vs. Vector
Scalar quantities express only a quantity and a unit
Vector quantities express a quantity, a unit and a direction
Examples:
| Quantity | Symbol | Type | Example |
| distance | Δd | scalar | Δd = 10 m |
| displacement |
 |
vector |
= 10 m [E] |
Note the arrow on the symbol for a vector .
.
It symbolizes the direction property of the vectory.
