Appendix C
Some Physical Constants
C.1. Mechanical and thermodynamic constants
| Speed of light in a vacuum (exact value) | c = 299,792,458 × 108 m/s |
| Gravitational constant | G = 6.67259 (85) × 10−11 N.m2/kg2 |
| Standard acceleration of free fall | g = 9.80665 m/s2 |
| Sideral year | 365.2564 days |
| Normal pressure | po = 1 At = l.01325 × 105 N/m2 |
| Normal temperature | To = 273.16 K |
| Mechanical equivalent of the calorie | J = 4.1855 (4) J/Cal |
| Mass density of dry air (STP) | ρo = 1.2929 kg/m3 |
| Speed of sound in air (STP) | vs = 331.36 m/s |
| Molar volume of ideal gases (STP) | Vm = 2.241383 (70) × 10−2 m3/mole |
| Avogadro number | No = 6.0221367 (36) × 1023 mole−1 |
| Boltzmann constant | K = 1.380658 (12) × 10−23 J/K |
| Gas constant | R = 8.314510 (70) J/K.mole |
| Acoustic impedance of air (STP) | Za = 428 N.s/m3 |
| Threshold of hearing sound intensity |  10−2 W/m2 |
| Stefan-Boltzmann constant | σ = 5.67051 (7) × 10−8 J/m2.s.K4 |
| Mass density of mercury | 13,595.5 kg/m3 |
Table C.1. Mechanical and thermodynamic quantities. Standard g means at sea level and at latitude of 45°. STP means standard temperature (0 °C) and pressure (760 mm Hg)
C.2. Electromagnetic and atomic constants
| Elementary charge | e = 1.60217733 (49) × 10−19 C |
| Electron-volt | eV = 1.6021892 (46) × 10−19 J |
| Planck constant | h = 6.626075 (40) × 10−34 J.s = 4.135669 (11) 10−15 eV.s |
| Reduced Plank constant | ħ = h/2π = 1.054572 66 (63) × 10−34 ... |
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