LESSONS OF EASTER ISLAND
March 17th, 2016
Properties of Typical Gaseous Fuels2
Calorific value

The efficiency of motor vehicles in the United States is commonly expressed in miles per U. S. gallon, while in most other countries it is expressed in liters per one hundred kilometers. To convert fuel economy stated in miles per U. S. gallon to fuel consumption expressed in L/(100 km), divide 235.215 by the numerical value of the stated fuel economy. Thus 24 miles per gallon corresponds to 9.8L/(100km).
4.4 U. S. Survey Foot and Mile
The U. S. Metric Law of 1866 gave the relationship 1m = 39.37 in (‘‘in’’ is the unit symbol for the inch). From 1893 until 1959, the yard was defined as being exactly equal to (3600/3937) m, and thus the foot was defined as being exactly equal to (1200/3937) m.
In 1959 the definition of the yard was changed to bring the U. S...
Read MoreSource: U. S. National Institute of Standards and Technology
Section 4.6 gives factors for converting values of quantities expressed in various units—predominantly units outside the SI that are unacceptable for use with it—to values expressed either in (a) SI units, (b) units that are accepted for use with the SI (especially units that better reflect the nature of the unconverted units), (c) units formed from such accepted units and SI units, or (d) decimal multiples or submultiples of the units of (a) to (c) that yield numerical values of convenient magnitudes.
The factors given in Section 4.6 are written as a number equal to or greater than 1 and less than 10, with 6 or fewer decimal places...
Read MoreGreek alphabet
A 
a 
alpha 
і 
1 
iota 
p 
q 
rho 
B 
b 
beta 
K 
К 
kappa 
R 
r 1 
sigma 
Г 
c 
gamma 
Л 
k 
lambda 
T 
s 
tau 
D 
5 S 
delta 
M 
i 
mu 
Y 
t 
upsilon 
E 
£ 
epsilon 
N 
V 
nu 
U 
/ u 
phi 
Z 
f 
zeta 
N 
n 
xi 
X 
v 
chi 
H 
g 
eta 
O 
o 
omicron 
W 
w 
psi 
© 
e » 
theta 
П 
p 
pi 
X 
x 
omega 
International system 
of unit prefixes 

Prefix 
Symbol 
Multiple 
exa 
(E) 
1018 (quintillions) 
peta 
(P) 
1015 (quadrillions) 
tera 
(T) 
1012 (trillions) 
giga 
(G) 
109 (billions) 
mega 
(M) 
106 (millions) 
kilo 
(k) 
103 (thousands) 
hecto 
(h) 
102 (hundreds) 
deka 
(da) 
101 (tens) 
deci 
(d) 
101 (tenths) 
centi 
The creation of the decimal metric system at the time of the French Revolution and the subsequent deposition of two platinum standards representing the meter and the kilogram, on June 22, 1799, in the Archives de la Ripublique in Paris can be seen as the first step in the development of the present International System of Units.
In 1832, Gauss strongly promoted the application of this metric system, together with the second defined in astronomy, as a coherent system of units for the physical sciences. Gauss was the first to make absolute measurements of the earth’s magnetic force in terms of a decimal system based on the three mechanical units millimeter, gram, and second for the quantities length, mass, and time, respectively...
Read MoreMeter The meter is the length of the path travelled by light in vacuum during a time interval of 1/299,792,458 of a second.
Kilogram The kilogram is the unit of mass; it is equal to the mass of the international prototype of the kilogram.
Second The second is the duration of 9,192,631,770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the cesium133 atom.
Ampere The ampere is that constant current that, 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.
Kelvin The kelvin, a unit of thermodynamic temperature, is the fraction 1/273...
Read MoreBecause of existing practice in certain fields or countries, in 1978 the CIPM considered that it was permissible for the units given in Table 7 to continue to be used with the SI until the CIPM considers that their use is no longer necessary.
TABLE 7 Units Temporarily Accepted for Use with the SI

1. GUIDE TO THE USE OF THE INTERNATIONAL SYSTEM OF UNITS
Source: U. S. National Institute of Standards and Technology
The International System of Units was established in 1960 by the 11th General Conference on Weights and Measures (CGPM). Universally abbreviated SI (from the French Le Systeme International d’Unites), it is the modern metric system of measurement used throughout the world.
SI units are currently divided into three classes:
• base units
• derived units
• supplementary units
which together form what is called ‘‘the coherent system of SI units.’’ The SI also includes prefixes to form decimal multiples and submultiples of SI units.
1.1.1 SI Base Units
Table 1 gives the seven base quantities, assumed to be mutually independent, on which the SI is fou...
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