Why is the ratio of two extensive quantities always intensive?
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Is this something that we observe that always happens or is there some fundamental reason for two extensive quantities to give an intensive when divided?
thermodynamics soft-question definition
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$begingroup$
Is this something that we observe that always happens or is there some fundamental reason for two extensive quantities to give an intensive when divided?
thermodynamics soft-question definition
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add a comment |
$begingroup$
Is this something that we observe that always happens or is there some fundamental reason for two extensive quantities to give an intensive when divided?
thermodynamics soft-question definition
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Is this something that we observe that always happens or is there some fundamental reason for two extensive quantities to give an intensive when divided?
thermodynamics soft-question definition
thermodynamics soft-question definition
asked 40 mins ago
paokara moupaokara mou
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984
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$begingroup$
It is mainly a mathematical reason. Extensive quantities grow with system size. If two quantities scale in the same way with a variable (in this case system size), it cancels out in the division.
Mini-example: $A$ and $B$ are extensive physical quantities both dependent on $n$. Their ratio is called $C = A / B$. If you scale the system up, $A$ and $B$ grow by a factor of $n$. What happens to $C$?
$frac{A cdot n}{B cdot n} = frac{A}{B}$
$C$ stays the same, irrespective of $n$. Hence, $C$ is intensive. The most common physical example is mass and volume, which scale with system size and still exhibit the same ratio, the density.
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1 Answer
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1 Answer
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active
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active
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$begingroup$
It is mainly a mathematical reason. Extensive quantities grow with system size. If two quantities scale in the same way with a variable (in this case system size), it cancels out in the division.
Mini-example: $A$ and $B$ are extensive physical quantities both dependent on $n$. Their ratio is called $C = A / B$. If you scale the system up, $A$ and $B$ grow by a factor of $n$. What happens to $C$?
$frac{A cdot n}{B cdot n} = frac{A}{B}$
$C$ stays the same, irrespective of $n$. Hence, $C$ is intensive. The most common physical example is mass and volume, which scale with system size and still exhibit the same ratio, the density.
$endgroup$
add a comment |
$begingroup$
It is mainly a mathematical reason. Extensive quantities grow with system size. If two quantities scale in the same way with a variable (in this case system size), it cancels out in the division.
Mini-example: $A$ and $B$ are extensive physical quantities both dependent on $n$. Their ratio is called $C = A / B$. If you scale the system up, $A$ and $B$ grow by a factor of $n$. What happens to $C$?
$frac{A cdot n}{B cdot n} = frac{A}{B}$
$C$ stays the same, irrespective of $n$. Hence, $C$ is intensive. The most common physical example is mass and volume, which scale with system size and still exhibit the same ratio, the density.
$endgroup$
add a comment |
$begingroup$
It is mainly a mathematical reason. Extensive quantities grow with system size. If two quantities scale in the same way with a variable (in this case system size), it cancels out in the division.
Mini-example: $A$ and $B$ are extensive physical quantities both dependent on $n$. Their ratio is called $C = A / B$. If you scale the system up, $A$ and $B$ grow by a factor of $n$. What happens to $C$?
$frac{A cdot n}{B cdot n} = frac{A}{B}$
$C$ stays the same, irrespective of $n$. Hence, $C$ is intensive. The most common physical example is mass and volume, which scale with system size and still exhibit the same ratio, the density.
$endgroup$
It is mainly a mathematical reason. Extensive quantities grow with system size. If two quantities scale in the same way with a variable (in this case system size), it cancels out in the division.
Mini-example: $A$ and $B$ are extensive physical quantities both dependent on $n$. Their ratio is called $C = A / B$. If you scale the system up, $A$ and $B$ grow by a factor of $n$. What happens to $C$?
$frac{A cdot n}{B cdot n} = frac{A}{B}$
$C$ stays the same, irrespective of $n$. Hence, $C$ is intensive. The most common physical example is mass and volume, which scale with system size and still exhibit the same ratio, the density.
answered 31 mins ago
lmrlmr
921518
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