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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Statistical Weighting Factor on thermal neutron importance

The problem is concerning the use of a thermal fluxed squared weighting factor in a thermal reactor. I have seen in sources the thermal flux in a reactor is squared as a statistical weighting factor, ...
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451 views

Ideal gas and diatomic gas with same temperature

If a box of ideal gas and another box of diatomic gas are in thermal equilibrium, does it mean that the average translational energy of ideal gas particle (A) is the same as that of diatomic gas ...
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505 views

Why there is no negative temperature [duplicate]

Possible Duplicate: Prove that negative absolute temperatures are actually hotter than positive absolute temperatures Proof of existence of lowest temperature $0 K$ On the Kelvin ...
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0answers
147 views

“This is not a perpetual motion machine, because reservoir temperatures are changing.” Is it a valid argument?

I've already faced this situation several times: given a statement (in area of thermodynamics) I used it to provide an example of some perpetual motion machine (of first or second kind). Therefore, I ...
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2answers
637 views

What happens when atoms speed up to extreme velocity?

The title might be misleading, but my question is in regard to what happens when we reach temperatures close to absolute zero (Kelvin). I've found different quotes as to what happens on the low end of ...
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3answers
879 views

How do Temperature Scales work?

How exactly do temperature scales work? If my understanding is correct, the Celsius scale has two fixed points: (definitions of temperature irrespective of scale) 1. The freezing point of pure water ...
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3answers
193 views

Heat Equation Equalities

While studying the heat equation, I ran into a few equalities that I cannot understand. For example, Fourier's law of heat conduction claims that $$\varphi(x,t)=-K_0\frac{\partial u}{\partial x},$$ ...
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1answer
105 views

Where does the heat flow in the Earth's crust switch from primarily solar to geothermal?

Ok, maybe more of a geology question than physics, but maybe somebody has been involved in modeling these heat flows? Essentially I'm asking if we know what sort of depth the heat source becomes ...
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1answer
1k views

How to calculate Temperature Humidity Wind Index?

I would like to know how to calculate Temperature Humidity Wind Index (THW Index)? I know how to calculate Heat Index and Wind Chill. I am asking this because my weather station Davis Vantage Pro2 ...
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1answer
748 views

Local Mach number for an airfoil

I would like to know how to calculate the local Mach number on the upper surface of an airfoil given the ambient temperature, the local velocity on the airfoil surface, the freestream velocity, and ...
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3answers
1k views

Is temperature an extensive property, like density?

I was thinking about it some time ago, and now that I've discovered this site I would like to ask it here because I couldn't work it out then. I know that the higher temperature the air in my room ...
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2answers
187 views

Using CO2 to air condition a room

I'm trying to determine how much dry ice or liquid nitrogen I would need to cool 3300 cubic feet, about 90,000 liters of air, from about 100F (37.78C or 310K) to about 90F (26.67C or 299.81K). I'm ...
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1answer
496 views

Calculating temperature of water in the freezer

Assuming water volume ($V$), initial water temperature ($T_0$) and environment temperature ($T_e$) are known, what is the easiest way to calculate temperature of water in given time ($T$)? For the ...
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3answers
1k views

Units of Distance, Pressure, and Temperature [closed]

I need to store data. I'd like to store them in Metric units and use a tool to convert them to and from other units that these data points will be displayed in. As the title states, my constraints ...
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1answer
174 views

Is it possible to use a powder-based firearm in space?

A firearm relies upon some kind of explosive powder to drive the slug out of the barrel. My guess however is that in space (at GEO, or higher) a firearm would be unusable due to the extremes of ...
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1answer
238 views

Temperature and latent heat

Building a bronze stature we make a mold and pour in the liquid bronze when the bronze hardens we remove the mold. The mold is made of 3 Kg of steel and the statue has a mas of 1 Kg. The specific ...
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2answers
4k views

Why I will feel colder when I get out from a swimming pool? [duplicate]

A friend of mine told me that because water heat capacity is higher. He also mentioned that it was similar to alcohol on skin effect. Assume that there are 3 situations. 1. I did not get wet 2. I got ...
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1answer
2k views

Why does blowing on someone who is wet feel colder than on someone who is dry?

The title says it all. If I'm standing in the wind and I'm wet, I feel much colder than when I'm dry. This is true no matter how warm or cold the water. Why is this?
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2answers
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Why is the temperature outside the airplane lower than the ground temperature?

seems the airplane is nearer to the sun, so the sun should more directly shine on the plane. But when I travel, the airplane temperature is much lower than the ground. Why is the temperature so low?
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1answer
1k views

Using resistance and temperature coefficient formula

What is the correct way to use the resistance and temperature correlation formula from http://hyperphysics.phy-astr.gsu.edu/hbase/electric/restmp.html? In particular, does R have to be the higher ...
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0answers
806 views

How to liquefy Hydrogen?

I have got a science project and my teacher has recommended me to do "Liquefying Hydrogen". I have been continuously thinking about that but I have not come to a solution. Can anyone please tell me ...
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5answers
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How do we perceive hotness or coldness of an object?

Some objects, especially metallic ones, feel cold on touching and others like wood, etc. feel warm on touching. Both are exposed to same environment and are in their stable state, so some kind of ...
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2answers
770 views

Do you pay more for gas when the day is warmer?

Found this at the gas station yesteday - got me thinking...
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1answer
123 views

What is a good reference for the mechanical properties of materials at cryogenic temperatures?

I want to research various the properties of various materials, namely tensile strength at cryogenic temperatures (~20K). I was wondering if a freely available database of material properties exists.
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449 views

Proof of existence of lowest temperature $0 K$

Im mathematics there is a concept of infinity meaning that whenever you pick a number and say that it is the smallest/Largest there is a way to further reduce/increase that number by ...
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1answer
167 views

If the temperature of 2 materials are the same does that mean the molecules are vibrating at the same speed?

Pretty much what the title says. My base question is this. Assuming I take a piece of steel, and a piece of PVC plastic and I measure both their temperatures and find they are the same. I then take a ...
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3answers
933 views

Opposite of Cryogenics

Cryogenics is related to very low temperatures, so, what is the term when referring to very high temperatures?
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1answer
827 views

Thermodynamics, bullet fired into ice

I'm beginning to study basic thermodynamics and I want to solve this exercise: It fires a lead bullet from $3g$ to $30^oC$ with a speed of $240\frac{m}{s}$ to a block of ice at $0^0C$. How much ice ...
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Light emitted by an object according to its temperature

According to this picture the light emitted by an object depends on its temperature. That makes perfect sense when we heat a metal. As its temperature raises we see it red at first, then orange, ...
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1answer
385 views

what will happen when I continuously heat a closed heavy iron box half-filled with water?

I mean what will be the situation inside? All water vaporized, Equilibrium, Temperature-pressure situation.. boiling point increase/decrease? Thanks for your time.
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1answer
1k views

Inductor with controlled temperature coefficient

Let's assume we have an air-spaced inductor made of copper wire. As temperature changes, due to thermal expansion of physical dimensions of the coil, its inductance changes too. 1) Is there a way to ...
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2answers
5k views

Will the hole on a metal disc expand or contract upon heating? [duplicate]

Possible Duplicate: Will a hole cut into a metal disk expand or shrink when the disc is heated? The metal disc of diameter D1 has a hole in it and the diameter of the hole is D2 (D2 Now, ...
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2answers
187 views

Correlation/relationship between human magnetic field and body temperature [closed]

Is there any relationship between human magnetic field and body temperature? I am looking for studies on this topic.
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3answers
105 views

Certain material heating water in a recipient

I don't know how to resolve a problem, but I don't want the answer since I'm almost going to have it resolved. What the problem says is we have 85 liters of water at 7ºC in an iron pot of 29kg. We ...
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5answers
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Is temperature in vacuum zero?

From Wikipedia entry on Kinetic Theory The temperature of an ideal monatomic gas is a measure of the average kinetic energy of its atoms. Now if I remove all the particles from the box shown ...
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1answer
191 views

In a Sterling Engine, does heat from the hot side transfer to the cold side?

A Sterling Engine is a closed system. The "hot" side oscillates between higher temperature with higher pressure and lower temperature with lower pressure. Does Nature switch back and forth between ...
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1answer
2k views

What's the temperature distribution of a plane wall insulated on one side with no internal heat gen.?

Let's say we have a plane wall that is insulated on one side, exposed to a fluid on the other side, and has no internal heat generation. Would the shape of the temperature distribution be a constant? ...
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1answer
846 views

Increase of threshold current by temperature in a laser diode

I read somewhere that if we increase the temperature of the material in a laser diode the threshold current for lasing also increases. Can someone explain to me why is this happening? What is the ...
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1answer
782 views

How do I find average temperature given a temperature distribution?

I was told to find the temperature distribution of a wire with a current going through it. So I found $$T(x)=T_{\infty}-\frac{\dot{q}}{km^{2}}[\frac{cosh(mx)}{cosh(mL)}-1]$$ I need to find the ...
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1answer
2k views

change of resistance in semiconductors due to temperature change

I have a question that popped up in an old exam I just can't find a way to solve. If you drop the temperature of this material from room temperature (I guess around 300K) to 0C (273K) the ...
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1answer
2k views

Heat Flux and Spatial Temperature Gradients

The derivation for Heat Equation I am reading starts by stating Net change of heat inside $[x,x+\Delta x]$ = Net flux of heat across boundaries + Total heat generated inside $[x,x+\Delta x]$ and ...
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1answer
306 views

What are conditions for the existence of a critical value (for a phase transition)?

Can there only be a critical temperature if there is some natural unit for an observable in the model, i.e. if there is a natural scale for something? Otherwise I don't see how for a system there ...
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1answer
647 views

Steady State Temperature of an Object Orbiting the Earth

This may be irrelevant or stupid to ask but I couldn't come up with a good answer. At least, we could not agree on with my friend the other day. I would like an estimate of the temperature of a human ...
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3answers
235 views

How to “read” the temperature of an abstract system?

How can I interpret the parameter temperature $T$, if I'm not given the description of the system in terms of the equation of state, $E(S,V\ )$ or $S(E,V\ )$ and so on. In many systems it makes sense ...
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1answer
564 views

Given two boiling temperatures and pressures, how can I find the latent heat?

I am given the fact that at a certain pressure a liquid boils at a corresponding temperature, at a different pressure it boils at a different temperature, and then I am asked to find the latent heat ...
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1answer
250 views

Is this a simple system in which no heat transfer is possible?

Let's say that a hot gas is trapped in a metal box. This metal box is magnetically suspended in another structure with a low temperature. The inner box does not touch anything. And there is a void in ...
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3answers
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How to understand temperatures of different degrees of freedom?

So I'm reading this book, where after the preface and before the models there is a section called General Notions and Essential Quantities, which introduce some things I don't understand. They regard ...
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3answers
564 views

Can temperature be defined as propensity to transmit thermal energy?

I was recently surprised to learn that defining temperature isn't easy. For a long time, it was defined operationally: how much does a thermometer expand. Also surprising, temperature isn't a ...
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1answer
194 views

Does a water cooker element have to be 100C to get water to cook?

I understand that a water heater element is basically just adding energy to the mass of water in the container. So does that mean that the heater element only has to keep adding energy while the water ...