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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How to do integration in the form below?

The original equation of Newton's law of cooling is $$\mathrm dT/\mathrm dt = -k(T-M),$$ but now I'm going to enhance the model, so I decide to add a variable which is $$\mathrm dT/\mathrm dt = -k(T-M)...
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Why do balloons get cold when they deflate?

When I deflate balloons by cutting one end and letting the air out, why does the surface of the balloon feel cooler?
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Is internal energy frame-dependent? [duplicate]

In the realm of kinetic theory of gases, the internal energy of gas is solely due to the sum of kinetic energies of all particles, since kinetic energy is frame dependent I was thinking whether a ...
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If our solar system was filled with air instead of the vacuum, would earth be colder or hotter?

Would the heat from the sun be transferred better to earth, since air is an isolator inferior to vacuum thus producing a hotter environment? Or would the energy be absorbed and dissipated in the air,...
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How do I determine the shape of steam?

When you dip a fork into a plate of hot food right off the stove and pull it out again with a forkful of food, it generates water vapour steam from the temperature difference. I am wondering how the ...
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Solid in Liquid Heat Transfer (Temperatures/Entropy Changes)

Suppose we have a solid of temperature $T_s$ and heat capacity $C_p$ submerged into a pool of water that has temperature $T_w$. If $T_s \gt T_w$ and the pressure of the isolated pool-solid system is ...
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Perpetual motion of zeroth kind?

Perpetual motions are classified by which law it breaks: Perpetual motion of first kind breaks the first law of TD. It generates energy from nowhere. Perpetual motion of second kind breaks the ...
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How much heat do colors absorb?

A common grade school experiment is to compare how hot different materials get in direct sunlight. See examples here, here and here for example. The premise is generally two identical objects of ...
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What is the difference between degree celsius and celsius degree? [duplicate]

It seems similar but can you guys please answer it that what is a specific difference between degree celsius and celsius degree?
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Open circuit voltage of solar panel in relation to temperature

How do we calculate the effect of temperature on the open circuit voltage of a solar panel? The source: https://www.pveducation.org/pvcdrom/solar-cell-operation/effect-of-temperature offers an answer,...
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Multiple heat sources on the same object, conduction only

If we have a bar of steel "AB" (or any type of material) exposure to a heating source (100 celsius for example) from the "A" end, assume conduction heat only. Now, I added a second heating source on ...
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Blackbody curves at low temperature

There is already a post here concerning a blackbody curve in visible light. The answer was helpful in that it stated that an object emitting visible light would emit some higher energy photons in x-...
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Mathematical formulation of the concept of temperature

We were taught the following. Consider three systems $A$, $B$ and $C$, which have exactly two independent variables each, $(X,Y)$, $(X’,Y’)$ and $(X’’,Y’’)$. Thermal equilibrium for $A$ and $B$ is ...
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Does warmer air of the same humidity condense faster?

Warmer air can hold more moisture but can it also release it's moisture faster when touching a cold surface? If air is warmed (for example by the hot side of a thermoelectric cooler ) before it moves ...
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Higgs critical temperature?

Higgs mechanism is defined to operate (give spontaneous symmetry breaking) below some critical temperature. As mentioned, for ex. in Wikipedia: Below some extremely high temperature, the field ...
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What are the practical reasons for have a high or low finesse value for a laser?

I was just wondering if someone could expand on what finesse of a laser cavity is, from my lecture notes I know how one would calculate it via the equation: $$F=\frac{4R}{(1-R)^2}$$ where $R$ is the ...
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Finding the temperature of a gas using the $P$-$V$ diagram [closed]

I need to know a way to relate the P-V curve of an ideal gas to its temperature.I found a similar question on stackexchange but couldn't understand how the relationship between a point and the ...
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Distance $E_F-E_i$ in a compensated semiconductor

Given two energy level diagrams for a compensated conductor: At $0~\text{K}$ At $500~\text{K}$ I want to determine for which diagram is the Fermi level closest/farthest from $E_i$. It's a ...
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Why do cool things warm up slower than hot things cool down?

EDITED After reading the answers and many of the comments, I realised I did not put nearly enough restrictions on this question. The scenario I am assuming is as follows: There are two cups of ...
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Do radioactive materials have a property for their natural heat output?

Consider room temperature, would a fissile/fissionable element be naturally warmer to the touch (or a sensitive thermometer) compared to say a glass of water (because the atoms have more ongoing ...
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The specific heat changes based on the actual temperature. How do I calculate the thermodynamic equilibrium when this value changes?

I have 2 substances with huge differences in temperature, with the specific heat of one starting at 0.6 J/kgC and ending at about 2.8 J/kgC. It goes from -200°C to 0°C. With this huge difference in ...
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In the equation $R = R_0 [1+αt(∆T)]$ is $R_0$ the resistance only at 0K/0°C?

For example, we're asked to find the resistance at a temperature 20°C, we know that the resistance at 10°C is 5 ohm, and we know the value of the temperature coefficient of resistance. Can we put Ro ...
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If I stood next to a piece of metal heated to a million degrees, but in a perfect vacuum, would I feel hot?

A friend of mine told me that if you were to stand beside plate of metal that is millions of degrees hot, inside a 100% vacuum, you would not feel its heat. Is this true? I understand the reasoning ...
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Would a micro black hole have enough energy to heat and liquefy the Earth from within without consuming it first?

Let's say an alien race drops a microscopic 72135 metric ton black hole into the center of the earth. It's Schwarzchild radius is too small (only 0.0001071103 femtometers) so it won't actually be able ...
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How hot can the surface of a planet be?

I just read this article https://edition.cnn.com/2018/07/02/world/newborn-planet-image-study/index.html and noticed that the astronomers estimates the surface temperature of the planet to 1000 °C. ...
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What is temperature on a quantum level?

When I was in high school, I learned that temperature is kinetic energy. When I learned statistical physics, we learned that temperature is a statistical thing, and there was a formula for it. ...
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How do window blinds work?

How do window blinds help to reduce the temperature in a room? On the one hand, I know that drawing the blinds helps my room to stay cool in the summer. On the other hand, just as much sunlight is ...
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Reduce temperature of fluid inside an isolated system without dissipating heat

Suppose you have a perfectly isolated system filled with a fluid, which cannot transfer heat nor matter to the external environment. Suppose you want to reduce the temperature of the fluid within ...
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Thermodynamic definition of entropy describing reversible processes

I've recently started learning about entropy. One possible definition is that it is the logarithm of number of microstates of particles. Another possible definition is that for a reversible (...
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Modelling behaviour of a transformer

I'm looking for a physical-mathematical model to describe the behaviour or working point of a power transformer in dependency on its most critical parameters like oil temperature/heat dissipation, ...
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What is the physical meaning of the Kondo Temperature?

From my understanding, in a Kondo lattice, the Kondo temperature is where the resistivity dramatically drops. I've also read that the Kondo temperature is the only real "scale" in the physics, with ...
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How do I approximate indoor temperature of a non-ventilated building?

How do I obtain a good approximate of the indoor temperature of a non-ventilated building (i.e., with no air conditioning) if I know the outside temperature (and possibly other factors, like humidity)?...
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Sun’s corona is so much hotter than Chromosphere [duplicate]

What makes Sun’s corona so hot? I tried to google it but can’t find satisfactory answer.
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Can we distinguish how an object was warmed up?

Suppose I warm a glass of water up to 50°C in the microwave. In the other hand, I warm up exactly the same amount of water to the same temperature, but in the oven. In this situation I would have two ...
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Warm or cold air

Which air can be used to dry out food or clothes? Warm or cold air? I've read that keeping food in the fridge makes it dry out. Blowing hot air to the hair also dries the hair out. I'm confused.
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Does elevation change the temperature at which snow falls?

I have read that snow falls at 32 degrees F. While at an altitude of nearly 8,000 feet above sea level, I found it snowing, but the temperature was more than 40 degrees F. Perhaps the indicator is ...
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Which is the most imminent doomsday? [closed]

By "doomsday" I define something which is caused by nature, given that the technological advancement of humanity stays the same as today, and also disregarding possible resource shortages. For ...
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Temperature equalization [closed]

I would like to ask you something about prevention of temperature equalization. I would really appreciate it if you can answer. To begin with, I want to store specific material(Thermoplastic ...
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Is the pressure inside a closed refrigerator same as atmospheric pressure?

What is the pressure in my deep refrigerator where water becomes ice. Is it lower than atmospheric pressure or higher or same? And how I can mesure it ?
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Decrease in temperature due to radiation

Can radiation cause the temperature to decrease? Because, in my Physics textbook, it is written that: ln winter nights, the atmospheric temperature goes down. The surfaces of windowpanes, flowers,...
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The Refractive Index of Water after Several Heating and Cooling Cycles

If the refractive index of water under a certain temperature, say 20 degreeC, is 1.33334. Will it return to exact the same value after one or several heating and cooling cycles? Or will it shift a ...
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Difference between sound and high temperature [duplicate]

Though vibration is a common concept in sound and “high temperature”, the essential difference between the two is mentioned to be the way the vibration takes place. The former has vibrations that ...
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Is there any known connection between temperature and resonance absorption frequency?

I'm aware of experiments showing that the frequency at which resonance absorption occurs using a Mössbauer absorber is affected by time-dilation. I was wondering if there were any experiments testing ...
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How does my body temperature stay lower than ambient air temperature if it goes over 37°C?

I know it's because of sweat, but why should the sweat over my skin get heat from the body, cooling it under the ambient temperature, instead of getting it from the hotter air all around me? If I ...
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How long does it take to cool down a drink with ice?

If I have a bottle or container with X fluid ounces of water at temperature Y (say, fridge temperature or room temperature), and I put ice or ice sticks (composed of water) in it that make up Z fluid ...
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Temperature anisotropy in plasmas

If a species of a plasma is described by a distribution function $f(\mathbf{r},\mathbf{v},t)$, is it possible to have different temperature (thermal energy) values for different directions (x, y and z)...
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Rising sea levels due to thermal expansion

According to NASA, one of the main reasons for the rising of sea levels is the increase in ocean temperature. The increase was of $0.4^\circ \text{F}\sim 0.2^\circ C$ for waters with depth $\sim700\...
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Density of states for fermions for temperatures other than absolute zero

Let's say I wanted to calculate the density of states for $\mathrm{2D}$ Fermions with an energy dispersion of $E_F=ck^6$ at $T=0$ The process would be quite mathematically simple. I'd take the ...
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Temperature Dependence of the Kubo Formula

I'm trying to calculate the DC conductivity of a Renormalized Fermi Liquid with Green's function \begin{equation} G(i\omega,k)=\frac{Z}{i\omega-Z\tilde{\epsilon}_k-ig\omega^2} \end{equation} where $...
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Deriving Planck's Constant from Wien's Displacement Law

So I'm reading an introductory book on Quantum Theory (David Park, 3rd ed.) and I am having trouble with the following question: "According to Wien's displacement law, the wavelength $\lambda_m$ at ...