Confusion on wording of a dimension problem

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The discussion centers on expressing the speed of sound waves in a gas in terms of pressure and density, represented by the equation v=ap^bq^c. The dimensions of pressure are clarified as m/((LT)^2), while the dimensions of density are confirmed to be m/L^3. Participants suggest using parentheses in the equation for clarity and recommend applying the Buckingham Pi Theorem to solve for the dimensionless constants b and c. The conversation emphasizes the importance of correctly identifying units for each term to resolve the confusion. Understanding these dimensions is crucial for accurately determining the values of b and c in the equation.
camillevoll
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the speed v of sound waves in a gas can be express in terms of the pressure p and the density q (mass per unit volume) of the gas, as v=ap^bq^c, where a, b, and c are dimensionless constants. The dimensions of pressure are m/((LT)^2). What must be the values of b and c.

I am confused on what to write for the dimensions of q. Would it be m/L^3 as in mass/volume?
 
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camillevoll said:
the speed v of sound waves in a gas can be express in terms of the pressure p and the density q (mass per unit volume) of the gas, as v=ap^bq^c, where a, b, and c are dimensionless constants. The dimensions of pressure are m/((LT)^2). What must be the values of b and c.

I am confused on what to write for the dimensions of q. Would it be m/L^3 as in mass/volume?

Welcome to the PF.

Could you add some parenthesis to your equation to eliminate the ambiguities?

"v=ap^bq^c"
 
v=a(p^b)(q^c)
 
camillevoll said:
v=a(p^b)(q^c)

Ah, that helps. Now can you fill in the units for each term? I usually use square brackets to indicate the units like v[m/s].
 
v=[L/T], p=[M]/[L][T^2]
 
Read up on the Buckingham Pi Theorem. That is what is involved here.

Chet
 
The book claims the answer is that all the magnitudes are the same because "the gravitational force on the penguin is the same". I'm having trouble understanding this. I thought the buoyant force was equal to the weight of the fluid displaced. Weight depends on mass which depends on density. Therefore, due to the differing densities the buoyant force will be different in each case? Is this incorrect?

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