ch.2

System International d'Unites

• SI

• base unit

• meter

• kilogram

a revision of the metric system used by scientist

• SI

• secound

• kelvin

• kilogram

a defined unit based on an object or even in the physical world

• base unit

• time

• temperature

• volume

second (S)

• time

• length

• mass

• temperature

meter (M)

• length

• time

• second

• mass

kilogram (kg)

• mass

• length

• temperature

• time

kelvin (K)

• temperature

• time

• length

• mass

the frequency of microwave radiation given off by a cesium-133 atom

• 1 secound

• 1 meter

• 1 kilogram

• the distance light travels through a vacuum in 1/299,792,458th of a second.

• 1 meter

• 1 secound

• 1 kilogram

• defined by a platinum-iridium metal cylinder

• 1 kilogram

• 1 meter

• 1 second