The metric system is used to measure the length, mass or capacity of an object. Length is measured in millimetres (mm), centimetres (cm), metres (m) or kilometres (km). Mass or ...

The metric system is used to measure the length, mass or capacity of an object. Length is measured in millimetres (mm), centimetres (cm), metres (m) or kilometres (km). Mass or ...

Historically, the changes in the height of the mercury were measured with a ruler, so barometric pressure used "inches of mercury" as a unit. Today, the metric units of the bar and the millibar are ...