Kevreyth Keswlasek Unsesow

Furv arnowydh an system metrik a vusur yw an Kevreyth Keswlasek Unsesow, (Frynkek - Le Système international d'unités}}; Sowsnek - International System of Units) selys war seyth unses elvennek ha devnydh an niver deg (10). 

Ottomma an system musur gwella gerys y'n bys, po yn diwysyans, po adhysk po godhonieth. Kevys yw ynwedh, unsesow moy degemerys warbarth ha rol an SI. 

Gwithys yw komendyans sodhogel dhe'n Kevreyth war wiasva NIST, ow komprehendya golinyans a gesberthynyans an unsesow an eyl dh'y gila. A-is yma rol a'n unsesow elvennel (kevys yw rol leun yn derivans (CODATA) a-dro dhe re erel kepar ha tooth golow.

An seyth unses elvennelseyth chif klass, ow settya rag-gorransow a-rag an henwyn. Pubonan a'n unsesow elvennel a sew yw sortow dyffrans a vusuransow. Pub unses aral a dheu dhyworth an seyth ma. 

+ An seyth unses elvennel SIBarry N. Taylor & Ambler Thompson Ed. The International System of Units (SI)  Adalwyd: Mehefin 2008; cyhoeddwr: National Institute of Standards and Technology, Gaithersburg, 2008Quantities Units and Symbols in Physical Chemistry, IUPACHanowArwodh an UnsesAn pyth yw musurysArwodhmetermhysl (lytheren vyghan)kilogramkggronnedhmeylenstermyntamperAfros tredanI (i: lytheren veur)kelvinKtempredhTkandelacdkrefter golowIv (i meur gans tanskrifans v)
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Rag-gorrans

+ Rag-gorrans savonys dhe ri a-rag an Unsesow Liessommen Hanow deca- hecto- kilo- mega- giga- tera- peta- exa- zetta- yotta- Arwodh da h k M G T P E Z Y Faktor 100 101 102 103 106 109 1012 1015 1018 1021 1024   Isklass Hanow deci- centi- milli- micro- nano- pico- femto- atto- zepto- yocto- Arwodh d c m μ n p f a z y Faktor 100 10−1 10−2 10−3 10−6 10−9 10−12 10−15 10−18 10−21 10−24

Nebes unsesow SI rag Fysegieth

+ An lythyerennek (Fysegieth)Pyth y musurysAn ger SowsnekSArwodhUnses savonekFurvelDyffrans potensyalPotential differenceVvolt, VV = I.RFrosCurrent Iamper, AI = V/RSprallansedh tredanelelectric resistanceRohm, ΩR = V/IDynedh tredanelelectric inductanceLhenry, HH = Ώ.sDalghasedh tredanel electric capacitanceCfarad, FF = s/ΏKargedhChargeQcoulomb, CQ = I.tRadyovewekter ha breynans radyovewekRadioactivity a Radioactive decayBqbecquerel1/s po A= -λNGallosedhPowerPwatt, WP = V.I po P = I2.RNerthEnergyEjoule, JE = Q.V po V = E/QTermynTimetEylen, sE = F.I po P.tForsedh ForceFnewton, NF = m.aGronnedh Massmkilogram, kgF = m.aPoosWeight neu forceWnewton, NW = m.gDosedh DensityDkg/m3, kg/m3D = m/VTorghedh Moment of force po torqueMnewton-meter, NmIM = F.lSkavder po toothSpeed neu velocityvmeter/eylen, m/sv = p/tUskisheans Accelerationameter/eylen2, m/s2a = Δv/t po a = F/mGwaskedhPressurePPascal, Pa (N/m2)P = F/A Arenebedh AreaAmeter2, m2A=s2 (s = hys an tu)DalghedhVolumeVmeter3, m3A=s3 (s = hys an tu)Menowghder Frequencyf po ν (ν = nu Grek)hertz, Hzf = 1/t (t = spys termyn)Tonnhys Wavelengthλmeter, mv = ν.λ (furvel ton)Ober gwrysWork po heatWdjoule, JWd = F.dNerth galladowPotential energyEPjoule, JEP = m.g.Δh (h = ughelder)Nerth kinetykKinetic energyECjoule, JEC= ½ m.v2