Absolute temperature

Содержание и основные понятия

The absolute temperature is proportional to the average kinetic energy of the flow of the molecules of the ideal gas.
GEF · 10 grade
PIF · Baseline
Interactive model
absolute temperature
Boltzmann permanent
thermal equilibrium
average energy
01
The physical picture
What happens and what boundaries the model has.
Main message
The absolute temperature is proportional to the average kinetic energy of the flow of the molecules of the ideal gas.
Temperature is a statistical value and is part of the multiple particle system.
The same temperature for different gases means the same average energy for the steady motion of molecules.
Calvin's scale does not have negative temperatures in the school thermodynamic model.
How to reason
First, name the system and the interaction, then select the values, and only then write down the law. The formula works within the model's assumptions.
02
Laws and values
Symbols should be read as a relationship of values, not as a recipe for substitution.
⟨
E
к
⟩
=
3
2
k
T
\langle E_{\mathrm{к}}\rangle=\frac{3}{2}kT
⟨
E
to
​
⟩
=
2
3
​
k
T
medium kinetic energy
T
=
t
∘
C
K
+
273.15
K
T=\frac{t}{^{\circ}\mathrm C}\,\mathrm K+273.15\,\mathrm K
T
=
∘
C
t
​
K
+
273.15
K
Transition to Calvins
Review of the situation
At 600 K, the average kinetic energy of steady motion of the molecule is twice that of 300 K.
04
Links and application
In the real world
At 600 K, the average kinetic energy of steady motion of the molecule is twice that of 300 K.
Model verification
Compare the prediction with observation, evaluate the units, the order of magnitude and the influence of the factors not taken into account. Disparity does not always mean an error of law: often idealization is no longer sufficient.
C
What needs to be understood
Outcome 1
Explain the physical meaning of the topic "Absolute temperature" through the model, not just the formula.
Outcome 2
Clear and correctly use terms: absolute temperature, constant Boltzmann, thermal equilibrium.
Outcome 3
Indicate the conditions for the applicability of the law, verify units and limit cases.
T
Terms of the topic
The definition should indicate the physical meaning, not a substitute for a domestic synonym.
absolute temperature
Thermodynamic temperature on the Calvin scale associated with the average thermal energy.
Boltzmann permanent
Basic constant, linking absolute temperature to the energy scale of particle movements.
thermal equilibrium
The condition in which the contacting systems have the same temperature and macroscopic heat exchange is stopped.
average energy
Statistical average energy of the particles or states of the selected system.
F
Origin and conclusion of the formulas
The fundamental law cannot be "proven" by algebras: for each record, it is stated whether it is a definition, an experimental law, or a model effect.
⟨
E
к
⟩
=
3
2
k
T
\langle E_{\mathrm{к}}\rangle=\frac{3}{2}kT
⟨
E
to
​
⟩
=
2
3
​
k
T
model effect
Medium kinetic energy.
The following is an indication of the definition, experience or law from which this entry arises and where it is applicable.
⟨
E
x
⟩
=
⟨
E
y
⟩
=
⟨
E
z
⟩
=
1
2
k
T
\langle E_x\rangle=\langle E_y\rangle=\langle E_z\rangle=\frac{1}{2}kT
⟨
E
x
​
⟩
=
⟨
E
y
​
⟩
=
⟨
E
z
​
⟩
=
2
1
​
k
T
The equalization theory gives kT/2 each independent quadratic progressive degree of freedom.
⟨
E
к
⟩
=
⟨
E
x
+
E
y
+
E
z
⟩
\langle E_{\mathrm{к}}\rangle=\langle E_x+E_y+E_z\rangle
⟨
E
to
​
⟩
=
⟨
E
x
​
+
E
y
​
+
E
z
​
⟩
The current energy of the molecule consists of the contributions of the three-axle motion.
⟨
E
к
⟩
=
3
⋅
k
T
2
=
3
2
k
T
\langle E_{\mathrm{к}}\rangle=3\cdot\frac{kT}{2}=\frac{3}{2}kT
⟨
E
to
​
⟩
=
3
⋅
2
k
T
​
=
2
3
​
k
T
The summation of three equal deposits gives the formula.
Conditions:
Classic equilibrium ideal gas; only particle movement is considered, quantum effects are ignored.
Monitoring:
The dimensions of both parts shall coincide; the result shall be checked for sign, order and limit case.
T
=
t
∘
C
K
+
273.15
K
T=\frac{t}{^{\circ}\mathrm C}\,\mathrm K+273.15\,\mathrm K
T
=
∘
C
t
​
K
+
273.15
K
definition
Moving on to the Kelvins.
The following is an indication of the definition, experience or law from which this entry arises and where it is applicable.
0
∘
C
=
273.15
K
0\,^{\circ}\mathrm C=273.15\,\mathrm K
0
∘
C
=
273.15
K
The Celsius scale is defined as Kelvin's shifted scale with the specified zero position.
Δ
T
(
K
)
=
Δ
t
(
∘
C
)
\Delta T\,(\mathrm K)=\Delta t\,(^{\circ}\mathrm C)
Δ
T
(
K
)
=
Δ
t
(
∘
C
)
The size of one Kelvin is equal to one degree Celsius for temperature differences.
T
(
K
)
=
t
(
∘
C
)
+
273.15
T\,(\mathrm K)=t\,(^{\circ}\mathrm C)+273.15
T
(
K
)
=
t
(
∘
C
)
+
273.15
The numerical value is therefore translated by adding a constant shift of 273.15.
Conditions:
For the conversion of the numerical temperature from degrees Celsius to cellines; for temperature intervals, 273.15 cannot be added.
Monitoring:
The dimensions of both parts shall coincide; the result shall be checked for sign, order and limit case.
!
Model boundaries and typical errors
Error: Forget model condition
The formula cannot be moved to any situation simply because of the coincidence of the letters. The key condition of this topic is that temperature is a statistical value and refers to the system of many particles.
How to Check the Mind
The same temperature of the different gases means the same average energy for the steady motion of the molecules. Then check the units, the direction of the vectors and the behaviour of the result at zero or very large parameter.
Σ
Conclusion on the topic
Absolute temperature
The absolute temperature is proportional to the average kinetic energy of the flow of the molecules of the ideal gas.
Temperature is a statistical value and is part of the multiple particle system.
The same temperature for different gases means the same average energy for the steady motion of molecules.
Any numerical result shall be accompanied by a unit, a sign and an explanation of its physical meaning.
The content is consistent with the FRP on Physics of the OS/OSS 2025 and the subject matter of the current lines of the PNP: I. M. Peryškin and co-authors (7–9), G. J. Mäkishev and coauthors (10–11), and with the lines "Engineers of the Future" and V. A. Kasyanov. The original texts are not reproduced, the text of the textbooks is not reproduced.