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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Can Maxwell's law of distribution of velocities be used to determine a value for absolute heat?

I'm currently reading about Maxwell's law of distribution of velocities, and the thought occurred to me that I could use this to calculate the maximum temperature that an atom could reach. My theory ...
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1answer
22 views

How does an object in vacuum loose its temperature? [duplicate]

Well, it radiates in the infrared, I guess. But how exactly are these photons created? The atoms have some kinetic energy, which makes up the temperature. So while the atoms or molecules jitter a bit ...
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2answers
400 views

Arrhenius Fit: Linear or exponential form?

I have a seemingly easy question about performing an Arrhenius fit to the equation $$y = A \times \exp \left( -\frac{E_A}{RT} \right)$$ I can either fit this in the exponential form using a ...
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2answers
1k views

What's the difference between a positive and a negative current?

Say I have a wire, and I connect a current source on its left end, and a ground to its right end. Then using my power supply I source a positive current, does this mean that electrons will move from ...
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1answer
93 views

Quicker way to cool liquid

I need to prepare a bottle of baby milk from formula quickly. To prepare it I must use some boiling water to sterilise the powder however it must be served at just above room temperature for the baby ...
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1answer
45 views

Need Some Help Creating A Couple Of Equations [duplicate]

I've posted about this project before as math is not at all my strong subject anymore. I have a couple sets of data and I need to make some equations for them. I've used Excel to get trend lines, but ...
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5answers
28k views

Why less temperature at high altitude

Why there is always cold at high altitudes. e.g. at peak of mountains. Also as we go high from sea level, temperature starts decreasing. Why is it?
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2answers
81 views

Temperature rise in Thermosphere

Generally speaking, temperature decreases as altitude increases from the sea level. But at the ozone layer it increases because ozone absorbs UV radiation. Temperature increases again in Thermosphere. ...
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5answers
180 views

What would the RBG color value of an infinitely hot blackbody be?

In other words, what is the limit of the rgb values of color temperature as temperature approaches infinity? Put differently, what is the terminal point of the Planckian locus? Is there an exact ...
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3answers
2k views

Can two bodies having the same internal energy have different temperatures?

According to me, two objects having the same internal energy may have different temperatures if their masses and specific heats are different and it is possible that an object with more internal ...
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0answers
87 views

Is temperature a frame dependent quantity? [duplicate]

The temperature of an object is proportional to the average kinetic energy (1/2*m*v^2) of its particles (or molecules), then shouldn't the temperature depend on the frame of reference since v^2 will ...
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1answer
853 views

Why isn't temperature frame dependent?

In (non-relativistic) classical physics, if the temperature of an object is proportional to the average kinetic energy ${1 \over 2} m\overline {v^{2}}$of its particles (or molecules), then shouldn't ...
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1answer
151 views

Why is temperature vibration?

Why do the atoms in a crystal vibrate at finite temperature?
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3answers
1k views

Why is boiling not just a surface phenomenon?

The boiling point of a liquid is defined as The temperature at which the vapor pressure of the liquid is equal to the external atmospheric pressure. That being the case, why, in a pot of boiling ...
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1answer
53 views

Do ice balls in whiskey really make sense?

So, I get the ad copy, the surface area to mass ratio results in more cooling, less dilution. But does this actually make sense? Yes, total cooling is related to the mass/temp of the ice, not the ...
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2answers
4k views

Can jet fuel melt steel beams? [closed]

Common sense suggests that steel beams should not yield under burning jet fuel without presence of other substances that produce very high temperatures when burning, such as thermite. So can jet fuel ...
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1answer
106 views

Calorimetry - Emitted Joules [closed]

How can one calculate the total amount of emitted joules from an object with a temperature that isn't constant? A great start is this formula: ...
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1answer
142 views

How to calculate water temperature from a room temperature? [closed]

e.g. My room temperature is about 33 degree celsius How can I calculate water temperature in the tank in my bathroom? Note that my tank is one side open up and it build up from bricks
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2answers
125 views

Help Writing An Equation [closed]

Truthfully, math past basic algebra was never my strong suit even though I went through stats in college. So I have to write an equation for this for a program and could use some help. I am reading ...
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11answers
54k views

Why does the gas get cold when I spray it?

When you spray gas from a compressed spray, the gas gets very cold, even though, the compressed spray is in the room temperature. I think, when it goes from high pressure to lower one, it gets cold, ...
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7answers
4k views

Why does heat added to a system at a lower temperature cause higher entropy increase?

Entropy is defined in my book as $\Delta\ S = \frac{Q}{T}$. To derive the formula it says that entropy should be directly proportional to the heat energy as with more energy the particles would be ...
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0answers
49 views

Equilibrium temperature of the universe [duplicate]

At what temperature will the universe eventually equilibrate?
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0answers
61 views

Entropy definitions

So I have learned that entropy is the measure of disorder of a system. For the IPhO this was of course not enough as we need to be able to calculate entropy changes of ideal gases. Those equations ...
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1answer
561 views

What's the most fundamental definition of temperature?

What's the most fundamental definition of temperature? Is it the definition concern about average energy, number of micro states, or what? By "fundamental", I mean "to be applied" in such general ...
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1answer
2k views

Thermodynamics for Dummies: Entropy and temperature

I do not study physics and I have never had a course in thermodynamics. I have no idea what it is about, but I am currently taking a course where we had something about entropy. Would be great if ...
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2answers
398 views

Dimensionless entropy interpretation

Measuring temperature in joules instead in the artificial units of Kelvin would render entropy as a dimensionless quantity. This is quite appealing since entropy has always been quite a misterious ...
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5answers
834 views

Integrating factor $1/T$ in 2nd Law of Thermodynamics

How would you prove that $1/T$ is the most suitable integrating factor to transform $\delta Q$ to an exact differential in the second law of thermodynamics: $$dS = \frac{\delta Q}{T}$$ Where $dS$ is ...
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2answers
2k views

Effect of temperature on radioactivity?

I'm researching the effect of temperature on uranium radioactivity, however I can't find any solid empirical evidence to prove the notion that temperature does not affect radioactivity. Can anyone ...
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0answers
42 views

Speed of electrons at given temperature in non Hydrogen-like atoms

I may be somewhat confused on the topic, so please excuse me if this is really basic. For the Hydrogen atom, one can easily derive the expectation value of the electron's speed: $$ \langle v \rangle ...
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1answer
179 views

why doesn't liquid metal vaporize in a vacuum?

I am wondering why molten metal in a vacuum of electron beam and machines never turns to gas like liquid water does when exposed to a vacuum.
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6answers
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Why does cold metal seem colder than cold air?

(I apologize for this elementary question. I don't know much about physics.) Let's say that I put a metal pot in the refrigerator for several hours. At this point, I guess, the pot and the air (in ...
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1answer
61 views

Melamine dish cools beyond ambient temperature

I have observed a phenomenon that I find hard to understand. A plastic, melamine like dish is filled with food (spaghetti, chile, soup, etc.) The dish and food is heated in a normal microwave oven ...
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1answer
71 views

Dynamic response of temperature change when identical fluids flowing mix together

As shown in the below figure , there is a mixing of a fuel in a system. the mass flow rates m1,m2 are different, the pipe diameters are all equal but are different in length.I need to get the ...
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0answers
25 views

What is the maximum level of heat that can be reached? [duplicate]

Heating is what everyone knows about . But does it have any limits . How much hot can anything become?
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2answers
60 views

Is the electrostatic field really static? Does thermal vibrations not affect it?

We know that if a conductor has any net charge, the charges reside on the surface. The electric field immediately outside the surface is perpendicular to the surface. But the charged particles, say ...
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1answer
167 views

Does a cooler, submerged in water, keep beer colder, longer?

Looking around the web, I see some submerged bucket-like things, without insulation, and some floating coolers, where the actual cooler is not submerged. Given that your water temperature is lower ...
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1answer
412 views

How does temperature affect the frequency produced by a fixed vibrating string

How does temperature affect frequency produced by a fixed vibrating string? In the case of the sonometer experiment, the length is fixed so temperature cant really affect length. It affects the ...
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1answer
61 views

Open systems (Conservation of Energy): is a temperature change possible if a tube is thermally isolated?

Full question: consider an perfectly thermally isolated cylinder. Water is flowing through this cylinder from the entry to the exit. Is it possible for the water flowing through the exit to have a ...
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2answers
82 views

Loss of temperature of a sphere [closed]

I am trying to get an intuition of whether it theoretically seems possible for a living cell (a yeast for example) to regulate its own temperature. Let's consider a spherical living cell which radius ...
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1answer
198 views

What does temperature coefficient of resistance depend on?

I tried looking up on Google if there was an expression for the temperature coefficient of resistance(TCR) of a material in terms of other fundamental factors, but couldn't find any. Specifically I am ...
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0answers
21 views

Luminosity and entropy of a relativistic shell

I am looking to understand more about gamma ray bursts. The review I am reading through describes in equations (111), (112) the luminosity of a relativistic plasma shell, in an inertial frame at rest ...
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1answer
26 views

Computing color and brightness of a hot material

Every blackbody color calculator I've managed to find only calculates hue and saturation; they completely ignore brightness, which severely limits their usefulness if you're trying to model the actual ...
3
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2answers
230 views

Does running water out of a faucet prevent the pipes from bursting? If so, why?

I have been told that, during especially cold periods during winter, one should run water out of the tap to ensure the pipes do not burst. Does this really help? If so, why? If true, at what ...
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2answers
116 views

Temperature of a Diamond in a Boiling Pot of Water

Suppose I have a boiling pot of water (100 degrees C) and drop a diamond in. Does the diamond eventually reach 100 degrees C? Since the diamond is a rigid structure, its molecules do not vibrate ...
3
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1answer
239 views

An object glows red at around 1000K while a red star is around 3000K. What causes this misalignment in spectra?

According to the H-R diagram, a red star is 3000K, a yellow star is 6000K and a white star 10000K. But a hot metal appears red at 1000K, yellow at 1500K and white at 2000K.(approximately) Why is ...
0
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1answer
124 views

What is the wavelength of a hot metal when its temperature 400 C? [closed]

I would like to know what will be the wavelength of a hot steel which temperature is 400 degree C
2
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1answer
106 views

Temperature dependence of spectra

I have a question that is short and sweet: Are spectra (both fluorescence and absorbance) of any molecule dependent on temperature? In particular, is the spectral lineshape function of any molecule ...
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2answers
56 views

The quickest way to reduce an isolated system's temperature

If you are in an isolated room, having an air conditioner and a ceiling fan. What is the quickest way to cool the room. Using only the air conditioner or both of them?
3
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1answer
145 views

Why doesn't water get 'increasingly thicker' as it gets colder?

It's my understanding that the colder liquids get (or anything else for that matter) the slower the constituting particles move. That being the case, why is H$_2$O either 'water' or 'ice'? Given that ...
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1answer
36 views

If an object's motion through space-time at speed $c$ corresponds to ageing, would cooling it down to slow ageing mean it doesn't move at $c$?

I get that all objects must move at the speed of light (c) in their reference frame because of the 2-part vector of space-time. For a case where the vector is pointing directly at time (because it is ...