19,879
edits
Changes
no edit summary
: '''SI''' [[unit]]s have been standardised around the world so that any [[experiment]] can be [[reproduce|reproduced]] and so that components in machines are interchangeable.
: The [[USA]] does not always use '''SI Units'''. As a result of the confusion over [[unit]]s a [[Space Probe|space probe]] once crashed on [[Mars]] because one team of [[scientist]]s was using [[inch]]es and the other team was using hundredths of [[metre]] ([[centimetre]]s).
The '''SI Units''' you should know are in the following table:
{| class="wikitable"
|-
|'''Measurement'''
|'''SI Unit'''
|-
|Distance, Displacement, Wavelength
|metres
|-
|Time
|seconds
|-
|Temperature
|degrees Celcius or Kelvin
|-
|Mass
|kilograms
|-
|Area
|metres squared
|-
|Volume
|metres cubed
|-
|Force, Weight
|Newtons
|-
|Speed and Velocity
|metres per second
|-
|Density
|kilograms per metre cubed
|-
|Angle
|degrees
|-
|Acceleration
|metres per second per second
|-
|Moment
|Newton Metres
|-
|Energy, Work Done
|Joules
|-
|Electrical Charge
|Coulombs
|-
|Electrical Current
|Amps
|-
|Potential Difference
|Volts
|-
|Resistance
|Ohms
|-
|Radioactivity
|Becquerels
|-
|Radiation Dose
|Ohms
|-
|Frequency
|Hertz
|-
|Magnetic Field Density
|Teslas
|-
|Moles
|Mol
|-
|Concentration
|Mol per decimeter cubed
|-
|Light intensity
|Lux
|}