What does quantities and dimensions mean?

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SUMMARY

The discussion clarifies the distinction between quantities and dimensions in physical measurements. A quantity, such as velocity or force, is expressed in units, while a dimension refers to the nature of the measurement, like length. It is established that two quantities can indeed have the same dimensions but different units, as illustrated by the example of height measured in inches versus centimeters. The conversation emphasizes that dimensions remain constant regardless of the unit system used.

PREREQUISITES
  • Understanding of physical quantities and their measurements
  • Familiarity with the concept of dimensions in physics
  • Knowledge of different unit systems (e.g., metric and imperial)
  • Basic mathematical skills for unit conversion
NEXT STEPS
  • Research the concept of dimensional analysis in physics
  • Explore unit conversion techniques between metric and imperial systems
  • Learn about the significance of dimensional consistency in equations
  • Study examples of physical quantities and their respective dimensions
USEFUL FOR

Students in physics, educators teaching measurement concepts, and professionals in fields requiring precise measurements and unit conversions will benefit from this discussion.

elton_fan
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i would like to ask a question about what does quantities and dimension mean in this sentence
is it possible for two quantities to have the same dimensions but different units?

thanks a lot in advance
 
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elton_fan said:
i would like to ask a question about what does quantities and dimension mean in this sentence
is it possible for two quantities to have the same dimensions but different units?

thanks a lot in advance


A physical quantity is something that can be measured, for example, velocity, force, etc. The quantity is expressed in units, which are not to be confused with the term 'dimension'. The term 'dimension' needn't be used, actually.
 
"Length" is an example of a dimension. The "meter" is an example of a unit, one that can be used to express lengths.

- Warren
 
so for example what would be the answer of this question?
i think it's yes
it's true
 
Last edited:
elton_fan said:
so for example what would be the answer of this question?

I'll answer your question with a question. How tall are you in inches? How tall are you in centimeters? Your height dimension is the same, no matter what units you use to express that height.

Think of a particular shipping box. It has linear dimensions of length, width and height. And those dimensions can be measured using various unit systems.
 
thanks a lot i understand now
 

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