Quantities and Unit Conversion

 

Quantities and Unit Conversion

Any measurement is always a multiple of some basic unit

Many units describe the same measurement

Quantities

All measure has to have 2 parts: the number and the unit

Numbers and unit combination are called quantities

SI (system International)- A French system dating back to the early 1800s using power of 10s

SI Base Units:

Measure	Unit	Abbacy
Length	Meter	m
Time	Second	s
Mass	Kilogram	kg
Amount of substance	Mole	mol
Luminous intensity	Candela	cd
Temperature	Kalvin	K
Electric Current	Ampere	A

Conversions

For converting meters and cm, we use the equation 1m=100cm since 100cm=1m 1=1m/100cm

Eg 5cm=0.05m

5cm/1 * 1m/100cm=0.005m

The main advantage of including the unit symbols is that you can keep tract of exactly what you are doing with calculation

Text	Symbol	Factor
tera	T	1,000,000,000,000
giga	G	1,000,000,000
mega	M	1,000,000
kilo	k	1,000
hecto	h	100
(none)	(none)	1
centi	c	0.01
milli	m	0.001
micro	μ	0.000001
nano	n	0.000000001