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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Temperature of rod if end points are different temperature [closed]

How does the temperature vary along the length of the rod if its both ends are at different temperature. As an example, consider the problem: 20 cm long rod has rod at one end 100 ºC and another ...
9
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2answers
280 views

In a large city how much hotter on average is it outside due to the air conditioning of all the buildings?

Title pretty much states the question. How much hotter do air conditioning units make it outside in a large city like NYC, Chicago, etc?
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698 views

Why do we feel a sudden chill?

When we are in a room, especially in some old houses, we feel this sudden rush of cold air. How does a strong air current arise and pass away so quickly?(lasts for about a second) I know air-currents ...
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40 views
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464 views

Ideal gas concentration under temperature gradient

I'm trying to calculate the concentration of an ideal gas in an adiabatic container as a function of position where the top and bottom plates of the container are fixed at temperatures $T_1$ and ...
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927 views

If you stop water from expanding, will its temperature stop rising?

Water expands when it heats up. If you heat water in a container that prevents it from expanding, will its temperature top out -- maybe around the boiling point? And if not, will it still turn to ...
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648 views

Guitar strings and temperature

I am investigating Mersenne's law with a guitar by varying tension (hanging weights) and string length. Will temperature change (room temperature to ~4°C) effect the frequency noticeably? If so, is ...
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2answers
378 views

Why do some air-conditioned stores blast you with jets of air as you enter?

I went to a grocery store on a hot day that was very well air-conditioned, and I noticed as I went through the open entrance that there seemed to be a very powerful downward air current right at the ...
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229 views

How to understand the thermal radiation?

I am studying the thermal radiation (Stefan–Boltzmann law) by myself $$P = \epsilon \sigma A T^4$$ here $\epsilon$ is the emissivity, $\sigma$ is Stefan-Boltzmann constant, $A$ is the surface area ...
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279 views

ideal gas law modelization in a vacuum chamber

I am trying to model a pressure sensor in COMSOL. The basic work is that there is current flowing inside it, if the pressure of the gas around it drops down, the temperature goes down as well (ideal ...
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Why does the air we blow/exhale out from our mouths change from hot to cold depending on the size of the opening we make with our mouth?

Why does the air we blow/exhale out from our mouths change from hot to cold depending on the size of the opening we make with our mouth? It's not just a subtle difference, but significant in my ...
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1answer
169 views

Negative temperature and Absolute hot

This video explains that heat at negative temperatures flows from the negative object to the normal object. If the temperature of the normal object is absolute hot, what happens with the heat? The ...
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1answer
122 views

Electromagnetic field to cool a substance?

I saw somewhere that an electromagnetic field would cause a substance to let off thermal energy, ultimately resulting in the substance to cool really quickly. If this is possible, does the strength ...
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1answer
488 views

How much does sunlight affect inside temperature?

Suppose we have a $3\cdot 3\cdot 3\,m^3$ room of which one side is glass. And suppose that the other 5 sides have no effect on temperature (super isolation). We know from physics how to calculate ...
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3answers
900 views

Best way to chill a cup of coffee with cold water and 5 minutes [duplicate]

Initial data 1 x 3/4 full cup of hot coffee / tea / your favorite morning beverage cold water 5 minutes Considering that it's starting to get hot outside, and we all want to drink reasonably cold ...
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1answer
866 views

Newton's law of cooling: changing temperature of environment

A metal ball having temperature of $80^\circ C$ is placed into $m$ grams of water at $0^\circ C$. After ten minutes, it was found that the temperature of ball and water are $60^\circ C$ and ...
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992 views

How fast would body temperature go down in space?

What would be the rate of temperature loss for an average sized human in space without a suit? A human generates about 100 watt at rest. But how can we use that to calculate how fast the temperature ...
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Can a rock be considered frozen

Water usually comes to mind when thinking about freezing. Once it reaches a certain temperature, water freezes, becoming a solid. However could you make the same statement about a rock? Is a rock at ...
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5answers
831 views

Having a problem about entropy, thermodynamics

I am a high school student. So, while studying about thermodynamics, I got a little curious about entropy. As I read, entropy is the rate of change of chaos. So, if the entropy change of a system is ...
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1answer
393 views

Why do ice cubes make a cracking sound when placed in fizzy wine (Prosecco)?

When placing ice cubes in a fizzy drink such as Prosecco, ice makes a cracking sound, after which the fizzy bubbles more than usual. What is the physics of this phenomenon?
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62 views

Which is more efficient cooling? Cooling yourself from cold water from Referigerator or Airconditioning? [closed]

Case a: You chill a glass of water in refrigerator to a certain temperature and drink it.. it lowers your body temperature by X degrees. Case b: You switch on the a/c for a certain duration.. it ...
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8k views

High and low pressure area and raining

In the high-pressure area it is mostly likely that there is sun. In low pressure area it is mostly likely that rain will occur. Because of the law that ...
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2answers
429 views

Any example of lower symmetry in high temperature phase than the low temperature phase?

All the phase transition cases I came across so far have this property: the lower temperature phase has lower symmetry than the higher temperature one. But it is nowhere explicitly said that, lower ...
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1answer
496 views

How long does the 2nd pot of water take to boil right after the 1st one finishes?

Say I have a pot of water that boils in 20 minutes, at whatever temperature. If I leave the fire on, take the pot off, pour the hot water into a container, refill the pot with tap water and put it ...
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702 views

Why isn't the Earth's core temperature the average of its surface temperatures?

Assuming that the earth is spherical, that its temperature is continuous, and that some other more or less realistic conditions hold, we might think that the Earth's core temperature should be about ...
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1answer
298 views

Temperature gradient in body [closed]

Is there a Temperature gradient in the human body? especially I have heard that the eye is colder than other places? Is that right?
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2answers
4k views

Why is a degree Celsius exactly the same as a Kelvin?

How on earth is it possible that the difference between two temperatures in Celsius and Kelvin is exactly the same. Given the historical definition of Celsius, I find it hard to believe that this is ...
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968 views

Can a single molecule have a temperature?

A show on the weather channel said that as a water molecule ascends in the atmosphere it cools. Does it make sense to talk about the temperature of a single molecule?
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1k views

Are Colors Emitted at Specific Temperatures?

There are quite a few nagging questions I have been having over the years, I do not require a full explanation, just some guidance in my assumptions and pointers if I am very wrong. My basic ...
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2answers
458 views

Why is the temperature zero in the ground state?

This is probably a simple question: I see this claims in many books, but I can't figure a reason why this is true. So my question is why this claim is true: "If we know that the system is in the ...
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3answers
850 views

What is the general statistical definition of temperature?

Temperature in an isolated system is defined as: $$\frac{1}{T} = -\frac{\partial{S(E,V,N)}}{\partial{E}} $$ But I wonder how one can generalize this to a random system. Or for instance to a point in ...
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1answer
257 views

Does brown but transparent swimming pool water heat significantly faster than western style highly chlorinated pools?

Eastern European swimming pools are often brown tinted water. i was told it was the color of the chemical to keep the pools clean, but who knows. These pools did not smell unsanitary and may have even ...
2
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2answers
90 views

What is the derivation for the exponential energy relation and where does it apply?

Very often when people state a relaxation time $\tau_\text{kin-kin}, \tau_\text{rot-kin}$,, etc. they think of a context where the energy relaxation goes as $\propto\text e^{-t/\tau}$. Related is an ...
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1answer
57 views

Speed of air through valve

Right now I'm working on a hot air balloon in Physics formulas. At the moment it's flying up like it should, but once it is at a certain height we want it to go back down. After some research about ...
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188 views

Reflectivity of a glowing-hot metal surface

When a polished piece of metal (or steel in particular) is heated to incandescence, how do its reflective properties change? Given a mirror-like surface, would the object temporarily cease to act ...
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1answer
212 views

Ginzburg-Landau model for superconductivity

Could someone kindly elaborate more on the Simple Interpretation section from this Wikipedia Article? I refer to the part on the natures of $\alpha , \beta$. Why can one assume that ...
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126 views

Calculate how hot PLA will become

I am trying to attach the shaft of a brass heating tip to a PLA component. My problem is that the tip will have to reach a temperature of about 200°C and the PLA can only handle a temperature of about ...
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1answer
64 views

Temperature of a small system

What is wrong if I define temperature of a small system (I mean, a system which has not a large number of particles) by $$1/T = dS/dE$$ ?
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Heisenberg's uncertainty and $0 K$ temperature

when a body is subjected to $0 K$ temperature, it becomes rigid. hence if we see in terms of quantum the lattice vibration decreases, resulting in no change in the direction of the Random velocity, ...
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54 views

Negative temperature [duplicate]

How can we prove that if a negative-temperature system is in contact with a positive-temperature system, then the heat flow from the first to the second (and finally, the temperature of the second ...
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1answer
68 views

Is it physically meaningful to talk about the 'total temperature' of an object?

If I had a semi infinite, 1-D object and a finite 1-D object, both heated at the same constant rate at one end each for the same time period and both begin at the same initial temperature, is it ...
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2k views

How temperature gradient is a vector?

Everyone knows Temperature gradient is a vector quantity having direction from cold to hot.My confusion: why is temperature gradient vector if its direction is always fixed (as in the case of ...
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265 views

Heating and Recooling of an Object

Consider a piece of metal of length $L$ and linear thermal expansion coefficient $\alpha$. We eat the metal $\Delta T$ degrees, causing the metal to increase to length $$ L' = L + L \alpha \Delta T$$ ...
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1answer
2k views

Does gravity affects temperature reading of a mercury thermometer?

I remember when I was in primary school, the science teacher put me in charge of a mercury thermometer. I do not quite understand the mechanics behind except that mercury expands when it is hot and ...
21
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6answers
3k views

Why isn't temperature measured in Joules?

If we set the Boltzmann constant to $1$, then entropy would just be $\ln \Omega$, temperature would be measured in $\text{joules}$ ($\,\text{J}\,$), and average kinetic energy would be an integer ...
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225 views

How hot would space feel?

I read that the temperature of the space around the earth can vary greatly depending on whether or not it is in direct sunlight. Space, however, is not very dense, so I imagine that heat would not ...
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1answer
4k views

What are the temperatures of objects in Low Earth Orbit (LEO)?

What is the temperature of objects in Low Earth Orbit? Consider LEO to be 600km to 800km.
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How long can you survive 1 million degrees?

I asked my Dad this once when I was about 14, and he said that no matter how short the amount of time you were exposed to such a great temperature, you would surely die. The conversation went ...
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2answers
914 views

What's the avarage temperature of the Universe?

I'm sorry if this was asked before but with all the stars and dark matter and all the other stuff, curently in the Universe, what's the avarage temperature of the Universe? Is it like extremely high ...
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How is gradient the maximum rate of change of a function?

Recently I read a book which described about gradient. It says $${\rm d}T~=~ \nabla T \cdot {\rm d}{\bf r},$$ and suddenly they concluded that $\nabla T$ is the maximum rate of change of $f(T)$ ...