Tuesday, May 27, 2008

The International System, or SI (cont-1)

Mass

The standard of mass is the mass of a particular cylinder of platinum-iridium alloy. Its mass is defined to be one kilogram, and it is kept at the International Bureau of weights and Measures at Sevres, near Paris. An atomic standard of mass would be more fundamental, but at present we cannot measure mass on an atomic scale with as great precision as on a macroscopic scale.

Next: The International System, or SI (cont.2)

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