Wht is the standard unit of mass?

Answer 1

The standard (SI) unit of mass is the kilogram (kg). It's NOT the gram!

Until it became officially known by its current acronym in 1961 ("SI" is officially used in ALL languages, it stands for the French locution "Système International d'unités") the International System of Units was known as MKSA after the names of the 4 fundamental units it's based on, namely: meter for length, kilogram for mass (indeed!), second for time and ampere for electrical current.

The kilogram is the only basic SI unit which is still based on a unique artifact (the prototype made of Pt-Ir alloy preciously preserved in the "Pavillion de Breteuil" near Paris, France). Other units are now defined by a reproducible property of some definite stuff (the SI second is the duration of 9192631770 periods of a cesium clock) or by enacting as exact the value of a constant of nature (the meter is defined in terms of the second by stating that the speed of light in a vacuum is exactly 299792458 m/s).

Answer 2

WTF pakinrat; first you say "gram" then you copy and paste stuff from http://ts.nist.gov/MeasurementServices/Calibrations/mass.cfm (without citing the source BTW) that states the NIST maintains "national standard for mass in the form of the prototype kilogram (K20) "

Then you say: "The rusty paris standard hasn't been the referance since 1948. Quit reading and referancing Wikipedia or you will know nothing."

but from http://www.mel.nist.gov/galleryph/calres/pages/049a.htm (there's that NIST again, this time with a link) we can find; "The picture is of the US National Prototype Kilogram. It is made of 90% platinum, 10% iridium. It was assigned to the US in 1889 and is periodically recertified and traceable to "The Kilogram" held at BIPM near Paris."

Answer 3

In SI units, Kilogram. In British units, the pound.

Answer 4

A kilogram of platinum living somewhere in Paris.

Answer 5

In science it would be a gram.

To packinrat: I gave you a thumbs down because you rushed to post an answer and then went back later and added the detail. I feel this is deceptive and dishonest.

Answer 6

mass is in kilograms etc (kg) force is newtons (N) speed is metres per second movement is the same as speed (which is measured in metres per second). - Edit - yes moment is in Newton Metres, sorry. (Well Newton Meters if you are in America) accelation is measured in metres per second square (with a little 2 at the end of it in superscript) it is the change [in metres per second] in speed / the time taken for that change to occur [in seconds] electric current is measured in amps

Answer 7

In the old CGS system it used to be gram. But in the universally adopted MKS system, it is kilogram.

Answer 8

Gram

NIST maintains the national standard for mass in the form of the prototype kilogram (K20) and provides services to support the parts of the national measurement system that rely directly or indirectly on mass measurements.

These services include the calibration of suitable weight sets. A calibration consists of establishing a mass value and the appropriate uncertainty for that value for each weight that has been designated to be a reference standard. It is desirable, but not necessary, that a weight meet the adjustment tolerances established for NBS Classes A, B, M, S, S–1, or equivalent prior to submission. Weights are available from manufacturers, many of whom can directly furnish documentation suitable for meeting quality assurance contracts and requirements.

NIST calibrates individual weights or sets in the range of 1 mg to 30 kg or 0.45 kg to 22.7 kg (1 lb to 50 lb) in decimal subdivisions. If the weights are designated as reference standards, they must be of design, material, and surface finish comparable to NBS Classes A, B, M, S, or S–1. These include ASTM Type I and II, classes 1, 2, 3, 4, and OIML E1, E2, F1 and F2. NIST also calibrates large mass standards 27.3 kg to 27 300 kg (60 lb to 60 000 lb) if the design, material, and surface finish are compatible with the intended usage. For these large mass standards, an adjustment with reference to a nominal or desired value can be included as a part of the calibration procedure.

In the absence of instructions from the customer, weights will be cleaned prior to calibration. If weights are to be calibrated "as found" (without cleaning), and returned without cleaning, customers should note this in their instructions to NIST. If weights are to calibrated "as found" and calibrated again after cleaning, double the fee will apply. The values of true mass (and an apparent mass correction) included in the report will be determined by using computed volumes based on the manufacturer's statement of density of the material, or on the density computed from measured volumes, or, in the absence of this information, on estimated density values.

The rusty paris standard hasn't been the referance since 1948. Quit reading and referancing Wikipedia or you will know nothing.

Answer 9

Imperial units, the POUND (lb). (0.4536kg)
In Metric, the KILOGRAM (kg). (2.2046lb)

Answer 10

grams