SOME PHYSICAL CONSTANTS
Rounded to 4 significant figures

Symbol	Value, Units			Name
-------	------------			-------

A	1.2e6 A/(m^2*K^2)		constant in thermionic emission equation
c	2.998e8 m/s			speed of light in vacuum
e	1.602e-19 C			electron charge
g	9.806 m/s			acceleration due to gravity
G	6.672e-11 N*m^2/(kg^2)		gravitational constant
h	6.626e-34 J*s			Planck's constant
h	4.136e-15 eV*s			Planck's constant
h-bar	1.055e-34 J*s			Planck's constant / 2 pi
h-bar	6.582e-16 eV*s			Planck's constant / 2 pi
h*c	1240 eV*nm			energy to wavelength conversion
k	1.381e-23 J/(K*molecule)	Boltzmann's constant
k	8.617e-5 eV/K			Boltzmann's constant
m-e	9.110e-31 kg			electron rest mass
N	6.022e23 molecules/mol		Avagadro's number
R	8.314 J/(K*mol)			gas constant
R	0.08206 l*atm/(K*mol)		gas constant
V-t	0.02526 eV			kT/e = thermal voltage at 68 F

epsilon-0 8.854e-12 F/m			permittivity of vacuum
mu-0	1.257e-6 H/m			permeability of vacuum
pi	3.142				pi
sigma	5.670e-8 W/(m^2*K^4)		Stefan-Boltzmann constant


SOME CONVERSION FACTORS
Rounded to 4 significant figures

1 eV = 1.602e-19 J
1 cal = 4.184 J
1 kcal/mol = 0.04337 eV/molecule
1 atm = 1.013 bar = 101,325 Pa = 760 Torr = 14.69 psi = 33.90 ft water
1 in = 2.540 cm
1 ft = 0.3028 m
1 mil = 25.40 um
1 mi = 5280 ft = 1760 yd = 1.609 km
1 mi^2 =  640 acres
1 gal = 3.785 l
1 ft^3 = 6.429 gal
1 fl oz = 29.57 ml ~ 30 ml --> 1 tsp ~ 5 ml
1 US barrel beer = 31 gal (although it varies)
1 cord wood = 128 ft^3
1 mi/hr = 0.4470 m/s
1 kg = 2.205 lbs
1 carat = 0.2 g = 3.086 grains
1 grain = 0.0648 gram, 7000 grains = 1 lb. Avd., 5760 grains = 1 lb. Troy
 Grains are the same in avoirdupois, troy, and apothecary measures.
 Q: Which weighs more, a pound of gold or a pound of feathers?  A: Feathers.
(Avoirdupois) 7000 grains = 1 lb., 27.34 grains = 1 dram, 16 drams = 1 oz.
Avoirdupois: 1 ounce = 437.5 grains, 1 pound = 16 ounces = 7000 grains; 
Troy: 1 ounce = 480 grains, 1 pound = 12 ounces = 5760 grains
At 554 nm, 1 W/m^2 = 683 lumens/m^2  (falls to 0 lm/m^2 near 400 and 700 nm)
1 lumen/m^2 = 0.0929 ft-candle = 1 lux = 0.001 phot
Sound: 0 dB = 1 pW/m^2 = 20 uPa
hc = 1240 eV-nm

SOME MEASURED VALUES

density of silicon = 2.328 g/cm^3   atomic density = 5.00e22 atoms/cm^3

Tungsten:  Tm = 3683 K, Tb = 5933 K, at wt = 183.9 g/mol
 at room temp: thermal exp = 4.5 ppm/K,  Cp = 134 J/(kg*K)
               elect resistivity = 5.65e-8 ohm*m, thermal cond = 174 W/(m*K),
               total emissivity = 0.032, density = 19.35 g/cm^3

Sound velocity: in dry air at 68 F = 331.5 m/s
                in water = 1497 m/s

1 gallon of water weighs 8.35 lbs