PhysicsLAB Resource Lesson
Metric Units of Measurement

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Given in the table below are the fundamental units of measure for the Systeme Internationale - or the MKS metric system. Also shown is a second popular collection of units is called the CGS system.
 SI fundamental units
Quantity NameMKS UnitCGS Unit
length metermcm
mass kilogramkgg
time secondss
electric current ampereA
temperature kelvinK
amount of substance molemol
luminous intensity candelacd
These are the basic units from which all other metric units of measure are derived. For example:
Speed is a derived quantity that expresses how rapidly an object travels a given distance with respect to time. It is measured in m/sec.
(scalar) quantity: speed
(formula) variable: r
units of measure: m/sec
Presented below are the most common derived units from mechanics. This link will take you to a more complete summary of the formulas and units of measure used in standard introductory physics courses.
namevector/scalarvariablecommon formulaunit of measurerelationships
lengthscalarL m1 m = 100 cm
heightscalarh m 
areascalarAA = Lwm21 m2 = (100 cm)2
volumescalarVV = Lwhm31 m3 = (100 cm)3
massscalarm or M kg1 kg = 1000 g
densityscalarDD = M / Vkg/m31 kg/m3 = 10-3 g/cm3
distancescalard m 
displacementvectors m 
timescalart sec 
speedscalarrr = d / tm/sec 
velocityvectorvv = s / tm/sec 
momentumvectorpp = mvkg m/sec 
accelerationvectoraa = Δv /Δtm/sec/secm/sec2
gravityvectorgg = GME/RE2m/sec29.8 m/sec2
forcevectorFF = ma  
MKS: kg(m/sec2)   nt, N (newton)
CGS: g(cm/sec2)   dyne
1 N = 105 dynes
tensionvectorT ntstrings, wires
spring constantscalarkF = ksnt/m 
impulsevectorJJ = Δp = Ftkg m/secnt sec
pressurevectorPP = F / Ant/m2Pa (Pascal)
workscalarWW = Fs  
MKS: kg(m2/sec2)   nt m = J (Joule)
CGS: g(cm2/sec2) erg
1 J = 107 ergs
energyscalarEW = ΔEkg(m2/sec2)nt m = J (Joule)
gravitational potential energyPEg = mgh  
elastic potential energyPEe = ½ks2  
kinetic energyKE = ½mv2  
powerscalarPP = W / t watt = J / sec
frequencyscalarff = #events / t1/sechz (hertz)
periodscalarTT = 1 / fsec 
anglescalarθ ° or radians90° = π/2 rads
torquevectorττ = FLm nt 
temperaturescalarT K or °C0 K = -273°C

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