SI Base Units Explained - Ch 2 Std 6

 

Below are common units of measure by category:

 

 

 

English (USA)

Metric

SI base units

1

Time

second

second

second

2

Length

in , ft. , yard, mi.

m, dm, cm, mm

meter (m)

3

Mass

oz., lb., ton

g, kg, mg, μg

kilogram (kg)

4

Temp.

F

C, K

K

5

Amount

doz., gross, pair

mole

mole

6

Electric curremt

ampere (A)

ampere (A)

ampere (A)

7

Luminous intensity

candela (cd)

candela (cd)

candela (cd)

 

SI Base Units (International System of Units)

The 7 SI Base Units in the last column of the chart above, are used in most scientific measurements. From these basic 7 almost all other units of measure can be derived. We will only use rows 1-5. Rows 6 & 7 are used commonly in physics.

 

Derived Units of Measure

Derived units of measure can be base units that are squared, cubed, etc. A few examples could be: m2 (gives area), m3 (gives volume), cm2 , cm3 (used as definition of mL) Derived units also come from dividing or multiplying different base units together. We will be using most of these examples during this course:

Examples:

density = which can have any of these derived units of measure and more:

or or

specific heat uses a derived unit of measure

molar heat of fusion uses a derived unit of measure

 

Other examples of derived units of measure are:

 

To print another copy of this page, go to my website and select:

Learning Center > Tutorials > Ch 2 > SI Base Units Explained (tutorial)

There is a great website that has very complete background on SI Units, and my video explaining this tutorial at:

Learning Center > Web Helps > Ch 2 > SI Base Units section and Wigger Vids section