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Questions tagged [temperature]

It's the physical property that indicates the degree/intensity of heat present in a substance or an object. It can be expressed and measured according to various scales.

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In thermal spas the temperature of steam is about $50^{\circ}C$, but feels way hotter. Why?

So when you're in hot water and start to move or something the steam feels really hot even though I read its temperature is about 50 degrees Celsius in thermal spas. So why does it feel that warm?
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Proving that $c_V$ is positive

On my professor's lecture notes he claims that $c_V>0$. Intuitively, this would have been my guess as well but he mentions how you can prove this by constructing a setup: "Construct an isolated ...
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What is temperature as a function of time in Fourier's Law?

Can we find temperature as a function of time using Fourier's Law of thermal conduction? For example: If we have two square parallel plates of a given length, width, and distance apart with one ...
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Is the acceleration of two objects with different temperature same with the same force? [on hold]

$F=ma$ is not the case at relativistic speeds. But what is the total energy including mass which resists against force?
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Can body of one temperature ever cause higher temperature in another body?

If you have one body that radiates heat at a constant rate and, forgive my simple assumption, thus constant temperature, and a body that may absorb this heat, may the temperature of second body ever ...
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Thermodynamics: Units in calculations of heat (Q)

When calculating an unknown variable in the quantity of heat equation for a system, let's say mixing water of 80 degrees C and ice of -20 degrees C that achieves thermal equilibrium at 10 degrees C (...
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Greatest volumetric heat capacity at very low temperatures

There is a theoretical device that I want to keep at a temperature of 3 K using a liquid helium coolant loop, and a block of material as heat sink, initially at 0.1 K. The main limitation is the ...
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Shouldn't a cold object feel less gravity? [on hold]

The premises for my question are, Gravity isn't a force but curved spacetime "If gravity isn't a force, how does it accelerate objects?" (complicated answer) If the answer below, to the question ...
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Probability at temperature in system has energy

Salutations, I'm starting in statistical mechanics and reviewing some related studying cases I would like to understand what occurs in small systems with normal modes of vibration, for example, a ...
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Adiabatic Flame Temperature and Oxy-fuel Combustion

When reading the wiki article on oxy-fuel combustion, it links me to the adiabatic flame temperature page. I understand that there are two types of adiabatic flame; constant pressure and constant ...
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Naive question about thermodynamics for use in a riddle

I am a mathematician with very little awareness of the physical world, begging for wisdom. I would like to have verification that my idealized physical model makes sense, for use in a riddle. I ...
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I am in doubt as to how I calculate $ΔH$ and $ΔS$ at $1700K$ for the transformation from graphite to diamond [closed]

I'm trying to solve this pressure exercise but I need to calculate ΔH and ΔS of Graphite and Diamond over the 1700K temperature and then calculate ΔG. Please, can anyone help me find ΔS and ΔH of ...
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Why is -273.15 °C the low temperature limit for the universe? [closed]

According to Ideal Gas Law the lowest temperature of an ideal gas can be $-273.15 °C$. This temperature is also considered the lowest temperature in the universe. But it is the lowest possible ...
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Calculating temperature of objects after colliding

So, I'm making a physics engine, and I need to know what is the temperature object A has after colliding with object B. Object A is 10 earths in diameter, and is 10 earths in mass. Object B is 5 ...
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How to calculate the ground state of Ising model at non-zero temperature

I'm studying the quantum Ising model, i.e. with Hamiltonian $H= -h\sum_{i}X_i-\sum_{\langle i,j\rangle}Z_iZ_j$. I know conceptually how to compute the ground state of the Ising model at zero ...
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How should I find an average for data that randomly fluctuates?

I have data for the temperature of a flame at a given height above the burner. The temperature fluctuates quite a bit (see figure), but there is definitely an "average" value that it tends to ...
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What equation describes the change of magnetic flux density based on temperature for a cylindrical neodymium magnet?

I have a neodymium magnet which I am subjecting to various temperatures and measuring the change in magnetic flux density using sensors. What is the theoretical formula that models this relationship ...
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Temperature at different points in a metal rod during heat conduction

$$ k = \frac{\frac{Q}{t}}{A(\frac{T_1 - T_2}{L})} $$ where k is thermal conductivity of the solid, Q is total amount of heat transferred, t is time taken for the heat transfer, A is area of the cross ...
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Why does the warm air rises up?

Warm air has more energy than cold air. This means that according to the Einstein equation $E = mc^2$ the warmer air has a greater mass than the cold one. Why is the warm air rising, if it has a ...
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Is absolute zero still 0 Kelvin?

Following the recent decision to change the definition of SI units, I understand that Kelvin is no longer defined in terms of the number 1/273.16. Does that mean that absolute zero is no longer ...
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How to arrive at the thermodynamic definition of entropy?

My question is, how do we say that, $$dS=\dfrac{dQ}{{T}} ~?$$ How do we relate heat and temperature to entropy? Why is the temperature in the denominator? Can we replace heat by work? How does ...
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Kelvin and kinetic theory of gases

I know that the degree of freedom increase by 2 when the temperature is high and decrease by 2 when the temperature is low. A dumb question here, what temperature is considered as 'high temperature' ...
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Why does a system assume ground state at absolute zero temperature?

I am going through Huang, Statistical Mechanics. He says at 0 kelvin, a quantum system assumes ground state so that $S=k_B ln(G)$ holds where $G$ is the degeneracy of the ground state . My question ...
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Capacitor open circuit voltage change with temperature

Given a charged, open circuit capacitor, and assuming leakage is negligible, does a change in temperature change the voltage? A capacitor's capacitance changes with temperature due to thermal ...
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How does a temperature change affect the pitch of the fundamental frequency produced by vibrating string? [duplicate]

The vibrating string is tightened using tuning keys of the guitar. Assuming the amount of tightening is constant, what will change in string (mass? tension? linear density?) when a temperature change ...
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What's the value for $\lim_{T\rightarrow 0}C_V$?

$C_V=\frac{1}{kT^2}[\overline{E^2} -\overline E ^2]$ where $\overline{E}^2=-\frac{1}{Z}\frac{\partial Z}{\partial \beta}$ and $\overline{E^2}=-\frac{1}{Z}\frac{\partial^2 Z}{\partial^2 \beta}$. $Z=\...
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My textbook sets $\ln \left\{ 1 + \left[ \frac{L}{L_0} - 1 \right] \right\}$ equal to $\frac{L}{L_0} - 1 $. What's the justification for this?

Sat to study physics. I started to study this new chapter Heat and Thermodynamics. It included these steps: $$ \int_{L_0}^L \frac{dL}{L} = \int_{\theta_0}^\theta \alpha d \theta; \text{ or } \ln \...
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An idea to model a one-dimensional thermometer?

Let's say I have a $1$-dimensional material with thermal expansion $\alpha$: $$ \alpha l_0 = \frac{\Delta l}{\Delta T}$$ where $l$ is the length of the system and $T$ is it's temperature. This is ...
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why high pressure systems are colder in temperate climates?

How do we derive equations which relate the temperature and pressure anywhere in the atmosphere? (assuming earth is still so no coriolis effect and flat if that makes the problem any easier). Like ...
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Why does the first peak of the temperature power spectrum of CMB imply a flat Universe?

According to Wikipedia, the first peak of the temperature power spectrum of CMB determines the curvature of the Universe. And this answer by @pela says that the first peak is consistent with a flat ...
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High temperature expansion in general

I'm referencing this thesis which should be open-access. In Appendix D.1 "High temperature expansion in general", the author writes the high temperature expansion in the following way: $$ \begin{...
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What is the current value for the temperature at which Recombination took place?

I'm looking for the most recent, most accepted value for the temperature at which the photon first decoupled from the atoms during the Epoch of Recombination? That is, what was the temperature of the ...
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How can I calculate the chemical potential and the effective masses in an intrinsic semiconductor?

I want to calculate the chemical potential and the effective masses of the germanium charge carriers considering that the relaxation time is the same for the two carriers: electrons and holes. ...
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Specific heat capacity is a function of temperature for ideal gases?

So far, I have the impression that temperature is the unit energy per unit entropy of a system. And entropy is some (logarithmically increasing) function of the average number of significantly ...
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Source and sink in an ideal reversible otto cyle?

what the temperature of source and sink is in an otto cycle? Since the temperature of the surroundings continuously change during the isochoric parts, we cannot have a single source and sink ...
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Is temperature equilibrium actually reached in a mixer tap, or is it merely a jumbling of hot/cold droplets?

Most kitchen and bathroom sink faucets have a mixer tap which blends the hot and cold inflows into a warm, uniform outflow stream. It's difficult to believe that complete heat transfer and ...
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Converting Wattage to Temperature [closed]

Let us say you have an 8 watt source or heater, what is the highest temperature it can attain or be converted to? I was asking in the context of transformer losses. At no-load, there is core loss.....
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Why are solar cells affected by temperature?

I know that solar cells efficiency increase with lower temperatures, but why? I found only equations on efficiency using temperature coefficient, but I want to know the physics behind it. Thank for ...
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Black body/Sun radiation - λmax

The Sun's effective temperature is 5778K. Using Wien's law we can calculate the wavelength λmax in which we observe the maximum amount of radiation received from the black body. After doing the ...
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What are the differences between anything at just above absolute zero and something just above the event horizon?

I believe an item that has a half-life would decay at the same rate regardless of temperature (maybe I am wrong on this assumption) but it would definitely slow down due to time dilation above an ...
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Why do system tend to attain thermal equilibrium anyway?

Ok, so I was reading a chapter on thermodynamics (introduction), which built its content on the idea that two systems separated by a diathermic wall will tend to attain thermal equilibrium with each ...
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Energy of room. Ideal gas law

I have been following Blundel's "Concepts of thermal Physics" and I got to the derivation of the ideal gas law. And it all made sense, we made a couple of assumptions and approximations, but then I ...
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Can Heat Transfer occur between two bodies with the same temperature but different states only through Latent Heat Transfer? [duplicate]

I understand that temperature difference is the driving force for heat transfer but I have been wondering whether there would be any heat transfer, let's say if steam at 100 degree Celsius and water ...
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Is flame temperature and the temperature above the flame about the same?

This is a practical question that looks not that academic. I'm trying to design an integrated forge that can do heating and forging together. Blacksmiths usually make a forge kiln like Figure 2, as ...
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Stress-Strain behavior of ceramics at high temperatures

Can someone explain to me why do we observe the peak in the stress strain behavior at 1400 C and then a sudden decline followed by gradual increase? What does it signify? Does it have anything to do ...
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Measure temperature of a heater wire

I would like to measure the temperature of a heating wire (tungsten) that's wrapped around my sample. Does anyone have a better idea than using a infrared thermometer, which has relatively low ...
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$u=(3/2)nRT$ when $T=0$

Why does a body with $0\ K$ temperate does the internal energy NOT become $0\ J$? My lecturer said it had to do with some quantum mechanics, but I never really got any answers from him. I really want ...
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Specific heat of water in unit J/kg °F

We know that specific heat of water is 4186 J/kg °C This is the amount of heat per unit mass required to raise/change the temperature by one degree Celsius. We also know that ∆°C = 5/9 °∆F = ∆K (...
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Given two substances of different specific heats, how do you find the final temperature and these phase related things

Given two substances of different specific heats, how do you find the final temperature of them both, phase of either substance if there was a phase change, and how much either substance has changed ...
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How cold does Something need to be for String Theory to be relevant?

I’ve often read casually that in order for modern string theory and other competing quantum gravity theories to be tested absolutely enormous temperatures (or rather energy densities) are required. ...