History:

The metric system is the international decimal system of weights and measures based on the meter and the kilogram. The essentials of the system were embodied in a report made to the French national assembly by the Paris Academy of Sciences in 1791. Although modifications have been made since that time, primarily in regards to the precision of the basic units, the overall metric system remains unchanged. The term "metric" comes from the French metron (to measure).

Definitions of base units:

 

Length	meter or metre	m	Old: 1/10,000,000th the distance from the North Pole to the Equator New: 1,650,763.73 wavelengths in vacuum of radiation corresponding to the transition between the 2p10 and 5d5 in the krypton 86 atom
Mass	kilogram or kilogramme	kg	The mass of 1 liter of pure water at 4 degrees Celsius
Temperature	degree Celsius or Kelvin	° C or K	1/100th the difference between the melting point temperature and the boiling point temperature of water. Note: this is often replaced by Kelvin which has the same size degree but a zero starting point 273 degrees lower than Celsius (i.e., 0 degrees Celsius = 273 Kelvin). The term degree is also not used when using Kelvin.
Time	second	s	Old: 1/86400th of a mean solar day New: duration of 9,192,631,770 periods of radiation corresponding to the transition between two hyperfine levels of the groundstate of the atom of cesium 133.
Electric Current	ampere	A	that constant current, which, if maintained in two straight parallel conductors of infinite length, of negligible circular cross-section and placed 1 meter apart in vacuum, would produce between these conductors a force equal to 2 x 10-7 Newton per meter of length
Luminous intensity	candela	cd	in a perpendicular direction, of a surface of 1/600000 square meter of a black body at the temperature of freezing platinum under a pressure of 101325 Newtons per square meter
Amount of substance	mole	mol	amount of substance of a system, which contains as many elementary entities as there are atoms in 0.012 kg of C-12.

 

Metric Prefixes

 

yotta-	Y	1,000,000,000,000,000,000,000,000	1024	septillion
zetta-	Z	1,000,000,000,000,000,000,000	1021	sextillion
exa-	E	1,000,000,000,000,000,000	1018	quintillion
peta-	P	1,000,000,000,000,000	1015	quadrillion
tera-	T	1,000,000,000,000	1012	trillion
giga-	G	1,000,000,000	109	billion
mega-	M	1,000,000	106	million
kilo-	k	1,000	103	thousand
hecto-	h	100	102	hundred
deka-	da	10	101	ten
		1	100	one
deci-	d	0.1	10-1	tenth
centi-	c	0.01	10-2	hundredth
milli-	m	0.001	10-3	thousandth
micro-	m	0.000001	10-6	millionth
nano-	n	0.000000001	10-9	billionth
pico-	p	0.000000000001	10-12	trillionth
femto-	f	0.000000000000001	10-15	quadrillionth
atto-	a	0.000000000000000001	10-18	quintillionth
zepto-	z	0.000000000000000000001	10-21	sextillionth
yocto-	y	0.000000000000000000000001	10-24	septillionth

mks System that uses meters, kilograms, and seconds (we will be using this one)

cgs System that uses centimeters, grams, and seconds

SI Systeme Internationale - the metric system

 

Useful Conversions:

Although we will not be using the English measurement system in this class, here are a few useful conversions to know:

1 inch = 2.54 cm

1 kg = 2.2 lbs

1 mile = 1.61 km

1 km = 0.62 miles

°F = 9/5(° C) + 32

°C = 5/9(° F-32)

1 L = 1.06 qts

1fl. oz = 29.6 cm³

1 oz = 28.35 g