Find an Equivalent Law for Dimensionless Quantities

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SUMMARY

The discussion centers on finding an equivalent law for dimensionless quantities in a physical system described by the equation $f(E,P,A)=0$, where $E$, $P$, and $A$ represent energy, pressure, and area, respectively. The fundamental units identified are Mass ($M$), Length ($L$), and Time ($T$). Although the number of fundamental units equals the number of dimensional quantities, participants confirm that Buckingham's π theorem can still be applied to derive dimensionless quantities. The initial inquiry about the choice of fundamental units is validated, leading to further exploration of the theorem's application.

PREREQUISITES
  • Understanding of dimensional analysis
  • Familiarity with Buckingham's π theorem
  • Knowledge of fundamental physical units (Mass, Length, Time)
  • Basic concepts of physical laws and equations
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  • Study the application of Buckingham's π theorem in various physical systems
  • Explore examples of dimensionless quantities in fluid dynamics
  • Learn about the significance of non-dimensionalization in engineering
  • Investigate the role of dimensional analysis in experimental design
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Students and professionals in physics, engineering, and applied mathematics who are interested in dimensional analysis and the application of Buckingham's π theorem in deriving dimensionless laws.

evinda
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Hello! (Wave)

A physical system is described by a law of the form $f(E,P,A)=0$ where $E,P,A$ represent, respectively, enery, pressure and area of surface. Find an equivalent law that relates suitable dimensionless quantities.

I have tried the following:

The fundamental units are:

Mass: $M$, Length: $L$, Time: $T$.

Thus:
$$[E]=ML^{2}T^{-2} \\ [P]=ML^{-1}T^{-2} \\ [A]=L^2$$

In this case, the number of fundamental units is equal to the number of the quantities with dimensions, so we cannot apply Buckingham $\pi$ theorem , right?

But how else can we find an equivalent law that relates suitable dimensionless quantities? (Thinking)

Or have I done something wrong at the choice of the fundamental units? :confused:
 
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Hey! (Blush)

Those units are correct and they are dependent on each other.
I think that means that we can still apply Buckingham's theorem.
Did you try? (Wondering)
 

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