SI Units: Is the combination of SI units still an SI unit?

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Discussion Overview

The discussion revolves around whether the combination of SI units, specifically N/m², qualifies as an SI unit. Participants explore the nature of derived units within the SI system, questioning if combinations of base units inherently represent distinct SI units.

Discussion Character

  • Debate/contested

Main Points Raised

  • Some participants assert that N/m² is a valid SI unit, as it is a combination of recognized SI units (Newton and meter).
  • Others argue that while N/m² can be expressed as a combination of SI units, it does not necessarily constitute a distinct SI unit unless it has been assigned a specific name within the system.
  • A participant questions the classification of torque, suggesting that while it can be expressed in SI units, there is no singular SI unit designated for torque.
  • One participant points out that the SI unit of pressure is the pascal, which is equivalent to N/m², indicating a specific application of the unit.

Areas of Agreement / Disagreement

Participants exhibit disagreement regarding the classification of combinations of SI units. Some maintain that any combination is an SI unit, while others contend that it must have a specific designation to be considered a distinct SI unit.

Contextual Notes

The discussion highlights the ambiguity surrounding the definitions and classifications of derived units, particularly in relation to their physical meanings and nomenclature within the SI system.

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Homework Statement


Is N/m^2 a si unit
I know Newton is and meters
but togeather are there
or is m^2

Homework Equations


The Attempt at a Solution


N/m^2
m^2
 
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Find out if N/m2 has been assigned another name in the SI.
 
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In general you can't assume a combination of SI units automatically makes another SI unit.

Newton is a force.
m2 is an area.
So a N/m2 is a unit of what?
 
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Newton per meter square
 
CWatters said:
In general you can't assume a combination of SI units automatically makes another SI unit.
Why not? Any combination of SI units is another SI unit. Whether it is the unit of something physical or has its own name is another question, but it is still in the realm of the system.
 
So what is the SI unit (singular) of torque? You can express torque in SI units (plural) but there isn't an SI unit of torque. That what I meant.
 
ipipi favour said:
Newton per meter square

The SI unit of pressure is the pascal.
 

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