Special Numbers in The Metric System

Here are some special and interesting numbers in the Metric System:

Quantity Approximate ValueNotes
Speed of light (in vacuum) 300 000 000 m/s 3 x 108 in Scientific Notation
More accurately 299 792 458 m/s
Speed of sound (in air) 340 m/s Varies with temperature and pressure

Earth's gravity 9.8 m/s2 Varies by location

Distance from Earth to Sun 150 000 000 km Varies over the year
Distance from Earth to Moon 384 000 km Varies
Circumference of Earth 40 000 km
Height of Mount Everest 8849 m
Height of geostationary satellite 35 800 km

Freezing point of water 0°C Varies with pressure
Human body temperature 37°C Varies by person, site and health
Boiling point of water 100°C Varies with pressure

Atmospheric pressure 100 kPa Varies with weather and height

Density of water 1 g/cm3
(= 1 kg per liter)
Varies with temperature and pressure
Density of rock 3 g/cm3 Varies a lot based on type of rock
Density of gold 19.3 g/cm3