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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A thermometer in the wind

Consider two cases, Situation 1: a thermometer is stationary and air is blowing past it. Situation 2: the thermometer is moving with the wind, say on a car or something. Assuming now friction ...
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46 views

Is single tree shadow locally affecting air temperature?

In other words, is the air temperature under a single tree different from a couple meters away, in a hot day and under the sun? There are several effects potentially interacting: Tree transpiration ...
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32 views

Proving the existence of temperature from zeroth law in the MIT OCW notes

This question refers to the following set of lecture notes: ...
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54 views

Meaning of temperature during phase transition

Microscopically, temperature is related to the average kinetic energy of a system in thermal equilibrium. Both LIQUID water and GASEOUS steam can exist (independently) at a temperature of 100 degree ...
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79 views

What temperature is an evaporating cup of water at “room temperature”?

If I put 100 g of water in a cylindrical cup and I know it takes 2 weeks (lets say 1.2 × 106 seconds) at some RH/temp to completely evaporate in my room with a constant temperature, can I ...
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3answers
122 views

Why is the speed of sound lower at higher altitudes?

At sea level the speed of sound is 760mph, but at altitudes like the Concorde would fly at (55,000ft) the sound barrier is at 660mph, so 1000th slower. Does it have to do with lower pressure?
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Calorimetry Problem

I was doing a problem in thermodynamics where the net heat is 0. I dont understand why if you have say a copper calorimeter with water at say, 15C and add a mass of copper at a higher temperature say, ...
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1answer
25 views

Blue tarp temperature seems too cool with infrared thermometer [closed]

I have just measured under a blue tarp in direct sunlight and got 27C reading with my tiny infrared thermometer. I had just sprayed a toy with white paint on some newspaper. When I put the newspaper ...
5
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1answer
228 views

How far away from the Sun does space start to be cold?

I assume that if I stood on the sun, I would be hot. I similarly assume that if I stood about 10 feet from the sun, I would still be hot. However, if I stood in space 93 million miles away, I would be ...
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602 views

Why does William Herschel's experiment show red light as warmer than blue?

Why does William Herschel's experiment show red light as warmer than blue if blue light is higher energy? Here is an explanation of Herschel's experiment ...
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21 views

Can an object above absolute zero temperature exists in principle, if there is only one object in the whole universe and nothing else

It is said that: All matter with a temperature greater than absolute zero emits thermal radiation. For suppose, there is only object in the whole universe and it emits radiations above ...
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1answer
50 views

How does the temperature of a magnet affect its characteristics? [closed]

How does the temperature of a magnet affect its characteristics? Is a hot or cold magnet stronger? Or does it not matter?
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1answer
21 views

3D thermography setup

I want to know if its possible (yet) to sense the temperature throughout a given cylinder using non-invasive techniques? Such as ultrasonic or visual imaging etc. The temperature ranges from 250-450C. ...
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68 views

How do you calculate oxygen temperature as atm pressure changes? [closed]

I know that when gases are decompressed the atoms suddenly have a bunch of space and absorb all the heat around them thereby giving the effect that it is cool but how do you calculate this for oxygen ...
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3answers
88 views

When can we consider temperature and pressure as two independent properties of a pure substance?

I thought that pressure and temperature were always dependent properties on each other.But is there any state of a surrounding or condition when these two properties behave independently of a pure ...
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0answers
41 views

Why does it feel warmer when it is snowing? [duplicate]

It doesn't snow a lot where I live, but whenever it does and I go outside, the air feels warmer than I would expect on an clear day with an equivalent temperature, even though thermometer on my car ...
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2answers
36 views

Relative temperature sensitivity? [duplicate]

Why does the outside temperature feel cooler when the humidity is low as opposed to average or higher humidity levels?
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1answer
34 views

What is the temperature of a vacuum? [duplicate]

what is the temperature of Vacuum since temperature of a system is related to the average of the molecular kinetic energy and there is no molecule in a vacuum? i know there could be radiations but i ...
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2answers
29 views

Increasing water temperature without salt

I have been extremely curious on how to get water even hotter by couple more degrees when its boiling. Rather then adding salt .... I started to stirring it.. Same Concept works with cooling the ...
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0answers
46 views

2-loop $\phi^4$ at finite temperature [closed]

When evaluating diagrams that contribute to the 2-loop effective potential $V_{eff}$ in $\lambda \phi^4 $ theory at finite temperature one has to calculate diagrams of such type which equals to ...
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0answers
35 views

Highest temperature [duplicate]

The temperature of a body varies with the KE of its particles. The maximum KE can be obtained by making the atoms move about near the speed of light. Let us take the body as a gas so that the body can ...
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2answers
86 views

Why doesn't wind chill affect thermometers

I know that wind chill essentially works by 'wicking' more heat away from a substance, making it 'feel' cooler, but then why doesn't wind chill affect thermometers? Wouldn't the wind 'wick' heat away ...
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1answer
136 views

Why is the logarithm of the number of all possible states of a system differentiable?

Temperature of a system is defined as $$\left( \frac{\partial \ln(\Omega)}{ \partial E} \right)_{N, X_i} = \frac{1}{kT}$$ Where $\Omega$ is the number of all accessible states (ways) for the system. $ ...
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2answers
113 views

Temperature of fusion in the Sun vs. fusion in controlled experiments on Earth

I recently learned that hydrogen fusion (i.e., hydrogen to helium) experiments on Earth have been successful at temperatures in excess of 100,000,000 degrees Celsius. However, I also learned that ...
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1answer
74 views

Temperature dependence of magnetic domains

Does the size of magnetic domains depend on temperature ? Not able to find any papers on this subject, maybe because there is no such dependence...
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How many fixed points does a Kelvin scale have?

I have a book that says: In the absolute Kelvin scale, the triple point of water is assigned the value of 273.16 K. The absolute zero is taken as the other fixed point. But, then another ...
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0answers
16 views

Is delta temperature dependent on the initial temperature? [closed]

All computer hardware testing sites i know test cooling solutions (CPU/GPU coolers) based on the temperature difference from the initial (room) temperature. This is a good way to compare, but i don't ...
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1answer
48 views

Finding total thermal conductivity (Ksys) for n-number of connected materials

I was playing around with the idea of finding a "total" K value for 2 solid, flush touching pieces of metal. The original problem involved the two touching inline bars with a two different maintained ...
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45 views

What is the spheroidal temperature of water?

I understand that when a hot plate reaches a certain temperature water will no longer wet the surface, but will form perfect spheres on the surface of the plate. The temperature at which this happens ...
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2answers
239 views

Can a black hole have negative temperature?

Stephen Hawking said that black hole also have temperature and it is related to its mass so in other words a black hole can also be shown to have a negative temperature! I know that nothing is colder ...
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0answers
10 views

Reactor opening and total time to reach a specific temperature

Let's say I have a reactor (we assume that its shape can be approximated by a horizontal cylinder) in which there is air at the temperature of 1000K and at pressure of 1.5 bar. Now, I want to open it ...
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37 views

Why does an optical pyrometer read low in the open?

An optical pyrometer relies on the fact that the brightness of heat radiation from a body depends on its temperature. I have come across the fact that an optical pyrometer invariably reads low when ...
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0answers
45 views

Expansion in bimetallic strip

Suppose there is a bimetallic strip with thickness 't' .The coefficient of linear expansion on heating the metals are alpha 1 and alpha 2.Now if the bimetallic strip is subjected to a temperature ...
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3answers
37 views

Hot Chocolate- cooling itself down

If a hot cup of hot chocolate is just standing there, can it cool itself down by transferring the kinetic/thermal energy that the liquid has into the mug/cup?
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1answer
21 views

Why are negative temperature coefficient thermistors accurate for measurements of low temperatures?

Why are negative temperature coefficient thermistors accurate for measurements of low temperatures? How does higher resistance at low temperature accurately measure the temperature?
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1answer
53 views

Estimate post-shock temperature of nuclear explosion

I was recently shown a very interesting sequence of images depicting the expansion of the fireball of Trinity explosion, a nuclear weapon's test conducted in New Mexico in 1945. I read here that ...
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1answer
73 views

Maximum Temperature?

I have been reading a lot about wavelengths of light and Planck's law and such. Curious as to whether a minimum wavelength of $h$ (Planck's Constant) indicates that there is in some way an absolute ...
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58 views

First law of thermodynamics with additional term

I read in a paper that a "known expression for the heat received by a body" is $$dQ=dU+pdV-\mathbf{v}\cdot d\mathbf{P}$$ where $\mathbf{P}$ is the linear momentum of the body, $p$ is the pressure, ...
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1answer
57 views

How to calculate max temperature craft needs to withstand near the Sun

The Solar Probe Plus fact-sheet states that the craft will approach to the distance of 9 solar radii to the surface of the Sun (Approx 6.26e6 km) and its heat shields must withstand 1644K of heat. I ...
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1answer
49 views

Managing nuclear waste [closed]

Suppose you are trying to dispose of used uranium fuel rods. Once they are cooled and contained in zirconium pods, how would one try and send those pods to the earths core? This is all hypothetical. ...
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1answer
27 views

Compute affect of a shower on density altitude

As a pilot I have a basic understanding of density altitude, how temperature affects the effective air pressure: I noticed recently that I have difficulty breathing when I take a shower in Santa ...
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1answer
38 views

Infrared light and heat

I know that mid wave IR, long wave IR, and far IR are all infrared light that we feel as heat. Often, even when it is cold and windy, if I face the sun in a sunny spot it feels like it is 80 degrees F ...
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17 views

Cooldown of a 1 meter wide sphere of water at 10C° in space [closed]

I am wondering how long would it take for such a sphere of water to totally be under 0C°. Let's suppose that the surface tension is enough to keep the topology of the sphere intact an that it will ...
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1answer
355 views

If I mix 1 unit of water at at 30C° with 1 unit of water at 60C°, is the resulting water at 45C°? [closed]

I'm curious how temperatures work when mixing water. I'm not very good at physics but I'm always learning. Let's say I've 1 gallon of water at 30C° and 1 gallon of water at 60C°, and I mix them ...
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0answers
52 views

The effect of 8 hours 20 degrees C sunshine on the temperature of a stationary car's engine block? [closed]

What temperature of the engine block could be achieved by parking a car (Mazda 3) in full sunlight and facing south all day. Average day temperature 20 degrees Celsius no wind. And then how long to ...
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0answers
17 views

equation related to room temperature and air conditioner temperature and flow rate? [closed]

i want to find and equation that related the air room temperature and air conditioner temperature and flow rate. i want to model a cooling system. the input to the room are air conditioner supply and ...
3
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3answers
66 views

How do we know that the rate at which a body loses heat is proportional to the difference between its temperature and that of its environment?

Did someone do an experiment, or was that fact derived from other ideas we had about how the world works?
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5answers
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0 Kelvin body moving

As many books say: Temperature is (proportional, almost, etc...) average kinetic energy of particles. My question is this. "Suppose there is a body somewhere in empty space which moves at ...
0
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2answers
37 views

unit conversion issue

I have the following equation where $ T_0(x) $ measures the temperature in Celsius at point x. The parameter values are as follows. My question is how to handle the second term $Q_m \over ...
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1answer
36 views

Equilibrium temperature of closed system

Body X of temperature 0° C is brought into thermal contact with body Y of temperature 100° C. X has specific heat capacity higher than of Y. The masses of X and Y are equal. By my reasoning, the ...