Fundamental Quantities

Something can be measure and expressed by a value is called quantity, and generally it a unit.

A quantity use in science and tecnologi is a call a phisicall quantity.
Examples of physical quantities length, weight and time.

Ekample :

1.What quantity is being measure by this boy ?

2.What quantity is being measure by this man?

3.What quantity is being measure by this woman ?

4.What quantity is being measure by this man ?

The seven of fundamental unit of the International System

Fundamental Quantities	unit	abbreviation	dimension
Length	meter	m	L
Mass	kilogram	kg	M
Time	second	s	T
Temperature	kelvin	K	θ
Amount of substance	mol	mol	N
Luminous intensity	candela	cd	J
Electric current	ampere	A	I

Very large or very small numbers are difficult to express such as the earth’s radius or time between collisions in SI units.

So to make it simple, we use a prefix.

prefix	abbreviatin	factor
exa	E	1018
peta	P	1016
tera	T	1012
giga	G	109
mega	M	106
kilo	k	103
hekto	h	102
deka	da	10