In this article we will learn the relation between meter, centimeter, millimeter, inches, feet and yards. Stay tuned to learn more about how long is a meter! Meter is a metric unit of length. The abbreviation of meter is "m". Examples: Diameter of a swimming pool, length of objects. In order to convert the length given in meters to different units, it is needed to know the relation between the meter and the other units.
Hence, while doing the required length conversions, these relations can be used and the lengths can be converted easily from meters to the required units. Centimeter is also a unit of distance abbreviated as, "cm".
Millimeter is abbreviated as "mm". Inches is the USCS unit mainly used to indicate length. It is abbreviated as "in". Feet is also a USCS unit mainly used to indicate length. It is abbreviated as "ft". Foot is the singular unit for feet. Yard is the USCS unit abbreviated as "yd". Let us try converting these units to meters. We can use our arms with fingers extended and measures to the tips of the fingers. This is a freehand way to estimate meters, although there may be a small difference between actually measuring it with a scale and measuring it with your arm.
Learn Practice Download. Amazingly, a universally accepted value for the inch wasn't put into practise worldwide until July 1, , after a number of countries collectively signed the International yard and pound agreement earlier that year in February. The countries, which included, the US, Canada, Britain, South Africa, New Zealand and Australia came to the conclusion that an inch was to be officially and universally recognised as being So what made these fancy metric units so accurate that they were deemed better for measuring the length of an inch than barleycorns?
Well it's because the meter was derived from something everyone on Earth could use for reference, the Earth itself. The idea for the meter as a unit of measurement was first proposed during the French Revolution. As an example of just how necessary a universally accepted unit of measurement was needed, according to Ken Adler, author of, The Measure of All Things: The Seven-Year Odyssey that Transformed the World , there were around , different units of weights and measure in use in France during that time.
Now originally there were two proposed methods of discovering a standard unit of measurement; the first involved a pendulum with a half period of a single second.
The alternate idea put forward was to find the length of one quadrant of the Earth's meridian and divide it by 10 million. The French Academy Of Science opted for the latter due to the fact that gravity can vary ever so slightly depending on where you are on Earth, which would affect the swing of a pendulum and result in a standard, world-wide measurement being impossible to discern.
However, even though a method of deriving the unit was agreed upon in , the exact distance of one quadrant of the Earth's meridian wasn't known at that time.
What should have taken the two men little more than a year, actually ended up taking 7 years, which is where the title of Ken Adler's book mentioned above came from. Why did it take so long? Loads of reasons not the least of which was that they were frequently arrested during their respective journeys- traipsing around surveying things presumably looked suspicious to authorities during the French Revolution.
He failed to take into account that the rotation of the Earth made for a non-uniform shape. Nonetheless, it was decided that the meter would remain as realized in the platinum bar. Subsequent definitions of the meter have since been chosen to hew as closely as possible to the length of that first meter bar, despite its shortcomings. As time passed, more and more European countries adopted the French meter as their length standard.
However, while the copies of the meter bar were meant to be exact, there was no way to verify this. In , the Treaty of the Meter, signed by 17 countries including the U.
The intergovernmental organization, the International Bureau of Weights and Measures Bureau international des poids et mesures , BIPM , was also established at that time. The kilogram was the last of the artifact-based measurement standards in the SI. On May 20, , it was officially replaced with a new definition based on constants of nature.
After that first meeting, the BIPM ordered a new prototype and 30 copies were given to the member states. This new prototype would be made of platinum and iridium, which was significantly more durable than platinum alone.
The bar would also no longer be flat but have an X-shaped cross section to better resist distortions that could be introduced by flexing during comparisons with other meter bars.
Instead, the bar would be over a meter long and the meter would be defined as the distance between two lines inscribed on its surface.
Easier to create than an end standard, these inscriptions also enabled the measurement of the meter to survive if the ends of the bar got damaged. Official measurements of the prototype meter would occur at standard atmospheric pressure at the melting point of ice. Credit: NIST. And this was how it remained until , when precision measurement of the meter could make a quantum leap thanks to advancements made in a year-old technique known as interferometry.
In this simple, ideal setup, an individual light wave from a laser hits a beamsplitter, which creates two light waves traveling in different paths. One of the waves hits a moving mirror, which can vary its distance as it travels to the detector. Credit: S. It was in that NIST then known as the National Bureau of Standards advocated for the interference patterns of energized cadmium atoms to be made a practical standard of length.
This was useful because international measurement artifacts such as meter bars could not be everywhere at once; however, with proper equipment, scientists anywhere could measure the meter with cadmium.
Their copies, exquisite as they might be, are not as accurate as the real thing. Neither an artifact nor its copies are suited for every measurement one might want to make. To cite one real-world example, gage blocks are length standards commonly used in machining. Because of the extremely fine work demanded of machinists, their calibration standards must be finely crafted as well. Using cadmium and krypton wavelengths, gage blocks could be certified to being accurate to within 0.
In the mids, nuclear physicists aimed neutrons at gold to transform the atoms into mercury. NIST physicist William Meggers noted that aiming radio waves at this form of mercury, known as mercury, would produce green light with a well-defined wavelength.
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