411 REFERENCE · Wikibooks
FHSST Biology/Units
Reference material by Wikibooks contributors. This retains its source identity and is not 411 news reporting.
Imagine you had to make curtains and needed to buy material. The shop assistant would need to know how much material was
required. Telling her you need material 2 wide and 6 long would be insufficient—you have to specify the unit
(i.e. 2 metres wide and 6 metres long). Without the unit the information is
incomplete and the shop assistant would have to guess. If you were making curtains for a doll's house the dimensions might be 2 centimetres wide
and 6 centimetres long!
It is not just lengths that have units, all physical quantities have units (e.g. time and temperature).
+ Table 1.1: SI Base Units
Base quantity
Name
Symbol
length
metre
m
mass
kilogram
kg
time
second
s
electric current
ampere
A
thermodynamic temperature
kelvin
K
amount of substance
mole
mol
luminous intensity
candela
cd
>> Next: Unit Systems