He concept from subway It has different meanings. From the Greek word métron, alludes to the unit length It is part of the international system.
In its origins, the meter was defined as the ten millionth part of the quadrant of the meridian of the land . Then it was decided to give greater precision to the unit: that is why, at present, the meter is equivalent to the distance that the light crosses in a vacuum in a period of 1/299 792 458 of a second.
This last definition of metro was adopted within the framework of the XVII General Conference of Weights and Measures that took place in 1983 . He symbol subway, on the other hand, is m .
The meter has multiples like decameter , hectometer and kilometer , and submultiples as millimeter , centimeter and decimeter . The use of one or the other depends on the convenience according to each case .
Also called the meter is the tool used for measurement of lengths . For example: "Pass me the subway, please, I must take the measurements of the furniture", "I suggest you use the subway to mark on the wall where you should make the holes".
Metro, on the other hand, is the quantity of something whose length is equal to one meter: “My grandmother gave me five meters of cloth to make the curtains”, "The vessel is equipped with fifty meters of fishing net".
The idea subway, on the other hand, can be used to refer to metropolitan . This is what in some regions is called train that makes an outdoor or underground tour of a city: “To go to the stadium you can take the subway”, “The subway was delayed by an accident and I was late for work”.