PHYSICAL QUANTITIES
SI (System International) system of units: 7 base quantities w/ fundamental units which are arbitrary

QUANTITY	SI UNIT
length	metre, m
mass	kilogram, kg
time	second, s
electric current	amperes, A
temp	kelvin, K
amt of subs	mole, mol
luminous intensity	candela, cd

physical quantity = measurable feature if diff items, has numerical value and unit
some phys quantity don't have units (quotient of 2 terms w/ same unit > unit cancelled; relative)
from fundamental units all other physical quantities can be derived (speed, m/s)
SI system based of multiples of 10 > metric

POWER	PREFIX	SYMBOL
1012	tera	T
109	giga	G
106	mega	M
103	kilo	k
10-2	centi	c
10-3	milli	m
10-6