Useful Constans

Constants

symbol	meaning	value
$e$ or $q$	Elementary charge	$1.60 \times 10^{-19}$coulombs
$\epsilon_0$	Vacuum permittivity	$8.85 \times 10^{-12}$ F/m
$N_A$	Avogadro constant	$6.02 \times 10^{23}\ mol^{-1}$
$k_B$	Boltzmann constant	$1.38 \times 10^{-23}$ J/K
c	Speed of light	$299792458\approx 3\times 10^8$ m/s
G	Gravitational constant	$6.67\times10^{-11} m^3\cdot kg^{-1}\cdot s^{-2}$
au	Astronomical unit	$149597870700$ m

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Mass

symbol	meaning	value
$u$ or $Da$	Unified atomic mass unit	1 u or Da in … … is equal to … $1.66 \times 10^{-27}$kg
$m_e$	Electron rest mass	$9.11 \times 10^{-31}$ kg
$m_p$	Proton mass	$1.67 \times 10^{-27}$ kg
$m_e$	Neutron mass	$1.67 \times10^{-27}$ kg
$M_\odot$	Solar mass	$1.98855\pm0.00025 \times 10^{30}$ kg
$M_\oplus$	Earth mass	$5.9722\pm0.0006\times 10^{24}$ kg

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