Finding values of constant by using Dimensional Analysis

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The discussion focuses on determining the constants a and b in the power law equation for the speed of sound in a gas, expressed as v = kpaPb, where k is dimensionless. Participants analyze the dimensions of both sides of the equation, equating them to find the values of a and b. The key point is that k can be excluded from the dimensional analysis since it is dimensionless. The next steps involve ensuring that the dimensions on the right side match those on the left, leading to the simplification of the equation. This process emphasizes the importance of dimensional consistency in physical equations.
Byeongok
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Homework Statement


The speed v of sound in a gas depends on the density p and pressure P of the gass. If this dependence is in the form of a power law that is,

v = kpaPb

where k, a and b are constants (k a dimensionless one).
a. Determine by dimensional analysis the values of a and b.
b. There by rewrite the above equation in a simpler form.

Homework Equations



v = kpaPb

The Attempt at a Solution


[/B]
I started off by writing the dimensions in the equation

[L][T]-1 = ( [M][L]-3 )a ( [M][L]-1[T]-2 )b

From here, i think i have to try and find the values for a and b that allows the right hand side of the equation to match the left. Also in this situation, do i just leave K out of it?
Any help to proceed to next step towards the answer would be great.
 
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Byeongok said:
From here, i think i have to try and find the values for a and b that allows the right hand side of the equation to match the left.
Right.
Byeongok said:
Also in this situation, do i just leave K out of it?
k is dimensionless, so it is irrelevant here.
 
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