Quick reference

For quick reference while studying, here are the fundamental constants, the SI units and the prefixes that recur throughout the book. It’s worth returning to this page whenever a numerical value is needed: memorising them isn’t necessary, recognising them is.

Fundamental constants

Constant	Symbol	Value	Unit
Speed of light in vacuum	$c$	$3{,}00\cdot 10^8$	m/s
Gravitational constant	$G$	$6{,}67\cdot 10^{-11}$	N m²/kg²
Coulomb constant	$k$	$8{,}99\cdot 10^9$	N m²/C²
Permittivity of free space	$\varepsilon_0$	$8{,}85\cdot 10^{-12}$	F/m
Permeability of free space	$\mu_0$	$4\pi\cdot 10^{-7}$	T m/A
Boltzmann constant	$k_B$	$1{,}38\cdot 10^{-23}$	J/K
Gas constant	$R$	$8{,}31$	J/(mol K)
Avogadro constant	$N_A$	$6{,}022\cdot 10^{23}$	mol⁻¹
Planck constant	$h$	$6{,}63\cdot 10^{-34}$	J s
Reduced Planck constant	$\hbar$	$1{,}055\cdot 10^{-34}$	J s
Elementary charge	$e$	$1{,}60\cdot 10^{-19}$	C
Electron mass	$m_e$	$9{,}11\cdot 10^{-31}$	kg
Proton mass	$m_p$	$1{,}673\cdot 10^{-27}$	kg
Acceleration due to gravity (standard)	$g$	$9{,}81$	m/s²

Fundamental SI units

Metre (m, length), kilogram (kg, mass), second (s, time), ampere (A, current), kelvin (K, temperature), mole (mol, amount of substance), candela (cd, luminous intensity).

Main SI prefixes

Prefix	Symbol	Factor	Example
giga	G	$10^9$	GHz, GW
mega	M	$10^6$	MJ, MW
kilo	k	$10^3$	km, kg
centi	c	$10^{-2}$	cm
milli	m	$10^{-3}$	mm, ms, mA
micro	$\mu$	$10^{-6}$	μm, μs, μF
nano	n	$10^{-9}$	nm, ns, nF
pico	p	$10^{-12}$	pm, ps, pF
femto	f	$10^{-15}$	fm (= 1 fermi)

Happy reading. The book works best when read pencil in hand, redrawing the diagrams and redoing the calculations: physics is only understood by doing it.

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