Constants

Universal Gravitational Constant G 6.67 ´ 10-11 N
m2/kg2
Ideal Gas (or Boltzmann’s)
Constant		 k 1.38 ´´ 10-23 Joule/K
8.62 ´ 10-5 eV/K
Stefan-Boltzmann Constant s 5.67 ´ 10-8 W/m2 K4
Gas Constant R 8.31 J/mol
K

Avogadro’s
Number

NA

6.02 ´ 1023 molecule/mol
Coulomb Force Constant k 9.00 ´ 109 N
m2/C2
Fundamental Charge e 1.60 ´ 10-19 C
Speed of Light in vacuum c 3.00 ´ 108 m/s
Planck’s Constant h 6.626 ´ 10-34 J
s
Planck’s Constant/2p 1.055 ´ 10-34 J
s
Rydberg (Bohr atom) constant R 1.1 ´ 107 m–1

Some Physical Properties

Density of Water rH2O 1 g/cm3
1000 kg/m3
Speed of Sound in dry Air at 1
atm and 20°C		 343 m/s
in Water at 1 atm and 20°C 1460 m/s
Earth’s Gravitational
Acceleration		 g 9.81 m/s2
Earth’s Radius rE 6.37 ´ 106 m
Earth’s Mass mE 5.98 ´ 1024 kg
Earth-Sun Distance (mean) 1 AU 1.49 ´ 108 km
Earth-Moon Distance (mean) 3.80 ´ 105 km
Electron Rest Mass me 9.11 ´ 10-31 kg
Proton Rest Mass mp 1.67 ´ 10-27 kg

Some Unit Conversions

1 mile = 1609 m 1 meter = 3.28 ft 1 in = 2.54 cm
1 mph = 0.447 m/s 1 day = 86400 sec 1 year = 3.16 ´ 107 sec
p Radians = 180 degrees 1 mm Hg = 133 Pa 1 atm = 1.01 ´ 105 Pascals
1 N = 0.225 lb 1 kg weighs 2.21 lb 1 Horsepower = 746 W
1 Joule = 0.239 cal 1 eV = 1.60 ´ 10-19 J

Compiled by J. Brennan, DVC Physics Dept.
1988. Please inform me of errors.