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PHYSICS
 

Platte Canyon High School
Bailey, Colorado

Useful Information

USEFUL INFORMATION
The Metric System

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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

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