International System of Units, SI

In 1960 an international agreement was reached specifying a particular choice of metric units for use in scientific measurements.

Notice the SI base unit for mass is the only base unit with a prefix.

 

The SI base unit of temperature is the Kelvin, K.

 

Derived units - those involving a calculation with base units.

• Area - length squared

  

• Volume = length cubed - cm³
   
  • 1 cm³ = 1 ml
     
  • One cubic decimeter is equal to one liter
   
• Density = mass / volume
   
  • The density of water at 4 ^oC is 1 g/cm³.

 
Prefixes are added to the base units to indicate decimal fractions or multiples.

SI Units named for people.

Scientific Measurement