List of Physical Constants
	Name	Symbol		Value
	Universal gravitational constant	G	6.67 × 10–11 N•m2/kg2
	Acceleration due to gravity	g	9.81 m/s2
	Speed of light in a vacuum	c	3.00 × 108 m/s
	Speed of sound in air at STP		3.31	× 102 m/s
	Mass of Earth		5.98	× 1024 kg
	Mass of the Moon		7.35	× 1022 kg
	Mean radius of Earth		6.37	× 106 m
	Mean radius of the Moon		1.74	× 106 m
	Mean distance—Earth to the Moon		3.84	× 108 m
	Mean distance—Earth to the Sun		1.50	× 1011 m
	Electrostatic constant	k	8.99 × 109 N•m2/C2
	1 elementary charge	e	1.60 × 10–19 C
	1 coulomb (C)		6.25	× 1018 elementary charges
	1 electronvolt (eV)		1.60	× 10–19 J
	Planck’s constant	h	6.63 × 10–34 J•s
	1 universal mass unit (u)		9.31	× 102 MeV
	Rest mass of the electron	me	9.11 × 10–31 kg
	Rest mass of the proton	mp	1.67	× 10-27kg
	Rest mass of the neutron	mn	1.67 × 10–27 kg