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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Why is the the temperature change due to the combustion of paraffin wax so high (10000 Kelvin)?

I'm trying to work out the temperature change (I got something like 10k Kelvin,hotter than the Sun's core...) caused by the combustion of paraffin wax which has a molar enthalpy of combustion $E^{wax}...
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Scattering cross section temperature dependence

In the book of Barbara Ryden, Introduction to Cosmology, the author states that $\sigma$ proportional to $T^2 $: Neutrinos interact with baryons via the weak nuclear force. At the temperatures we are ...
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Example of a body that receives heat but the temperature of the body decreases?

I am brushing up on my thermodynamics knowledge at the minute and am wondering if there is a process or circumstance in which a body receives heat but the temperature of the body decreases? In an ...
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How much more efficient is the nuclear fusion reaction of tritium and deuterium compared to two deuterons interacting?

Fusion is all the rage (again) these days, and most sources and popular articles claim that tritium-deuterium is the most 'efficient', with a cross-section of about 5 barns.... But what are the cross ...
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Should it be 1.5K instead of 1.5°C?

So everyone talks about how global warming should be limitted to 1.5°C. However, in my understanding the following conversion should be used: $${\displaystyle \left\{t\right\}_{\mathrm {^{\circ }C} }=\...
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Does boiling time changes if kept a fixed volume water in a pan with wider base and a pan comparatively less wider base?

Does boiling time changes if I kept a Given amount of volume of any liquid say water , 1. In a wider base pan 2. A comparatively less wider base cooking pan kept on a kitchen burner ?? (Both pan are ...
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Is it Possible for a System to have Negative Absolute Temperature?

The statistical definition of temperature is the following: $$\frac{1}{k_BT} = \frac{d\ln(\Omega)}{dE}$$ where $k_B$ is the Boltzmann constant, $T$ is the temperature, $\Omega$ is the possible number ...
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XY model free energy temperature limits

The free energy of the XY model for $ N \rightarrow \infty $ given by: $$ F = -\lim_{N\rightarrow\infty}\dfrac{1}{\beta N} \ln Z = -\dfrac{1}{\beta}\ln[2\pi I_0(\beta J)] $$ where $I_n(z) = \int_0^{2\...
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Correlation between critical temperature and spin-$s$ Ising models?

Why the critical temperature decreases as our $s$ of the spin system increase? Like a spin-1 system's critical temperature is higher than a spin(1/2) system. My reasoning is, since spin degrees of ...
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Effect of vessel shape on heating efficiency

I wasn't sure if this was best posted here or on the outdoors stack exchange. How much of a role does the size and shape of a vessel on top of a stove burner affect heating efficiency. I.e. for a ...
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How much does a radiator at 25˚C affect a room that is 20˚C?

This is probably not a very precise question but I'm just trying to get a rough idea how much effect a radiator set at such a low temperature would have on a room. Let's assume that the number of ...
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A frictionless piston contains 1 m3 of saturated water vapor at 250C. If it is cooled to a point where the mass fraction becomes 0.5, what is final T? [closed]

Came across this question recently in one of my thermodynamics courses, and I was not able to find a solution that worked. There seem to be too many unknowns about the final state, as all we know is ...
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Is the temperature of light affected by color filters?

This video demonstrates how varying color filters alter the energy of photoelectrons emitted from a light source: https://www.youtube.com/watch?v=kcSYV8bJox8 But I am confused by what these different ...
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Is there any other factor highly responsible for sensation of temperature except evaporation and reason behind thus scenario?

I am very confused from one contrasting situation , please help me to figure it out:- Suppose there is place let say A , there climate is hot or warm(say 30°c) "plus" humid (not 100%) what ...
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Controling the temperature in test tube

I am an electrical engineer and I am trying to control the water temperature in the test tube (laboratory application). But I can't measure the water temperature directly. I know what is the heater ...
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Inverting the heat equation

I have a wire that stretches from $x=0$ to $\infty$. The temperature at $x=0$ is given by the unknown function $f(t)$ for $t$ from $-\infty$ to now ($t=0$). I can measure the temperature of the wire ...
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Black body radiation: why can it glow yellow?

With black body radiation, light of different wavelengths are emitted in various proportions depending on the temperature of the emitter. Graphs of spectral radiance vs wavelength for different colour ...
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Does water become cooler when temperature increase so rate of evaporation increase?

We say rate of evaporation increase with increase in temperature either surrounding or of liquid! Does increased rate of evaporation due to increase in temperature cause increase in cooling? Because ...
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What actually we mean when we say "reaching 100% relative humidity and no further evaporation"?

What do we mean by reaching 100% relative humidity? Is that we reach the utmost vapor pressure at that particular temperature of liquid? Or something else. If I have 2 half filled water bottle, in one ...
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Why I feel cool in a region with lot of trees inspite of humidity by transporation?

Today I went for a walk and entered a region with lot of trees, It feel a sudden chill, a cool feeling (comparatively) Why, Although trees perform transpiration that cause moisture so we should feel ...
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Why is it said that it takes more energy to let a house cool down and heat up again, compared to keeping the temperature constant? [duplicate]

In nearly every webpage that I read on the topic, it is recommended to not let a house cool down over the day (even if nobody is there), but to instead keep a constant temperature. This is reasoned by ...
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Color temperature

To grow plants with artificial light, I need a device that can measure the wavelength of light and make sure I get the desired wavelength to the plant. This device is very expensive. Can I use the ...
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Work done in a $pV$ diagram

From what I gather, work done in a $pV$ diagram is the area under the curve. I have this figure here: The solution says the quantity of work in A is greater than that in B. I am kinda confused, aren'...
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Final temperature of water in cup $t$ seconds after ice is added

Suppose I have a paper cup and inside is 100g of hot water, say at a temperature of 90C. I let it cool in a room of ambient temperature 25C for 1 minute. Then, I add a 10g ice cube of temperature 0C. ...
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Why do some oranges freeze while others don't at the same temperature?

I buy fresh oranges wholesale so I could enjoy fresh juice every morning, I store them in the fridge (not the freezer) so they can last for a few weeks (yes, about 60% of my fridge content at any ...
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How does this author conclude that the volume of the gas is zero at -273.15 degree Celsius?

While reading Gaskell and Laughlin's Intro to ThermoD, I was stuck on something. The relevant passage is: "In 1802, Joseph-Luis Gay-Lussac (1778–1850) observed that the thermal coefficient of ...
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Is there such a thing as graviton temperature?

Are there purely gravitational degrees of freedom, and is there such a thing as a graviton temperature?
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How does the temperature of a solid sphere change when exposed to a hot environment?

I need to know how the temperature of an object will change with time when exposed to a time dependant increase in the temperature of the environment. I only require an approximation and I thought I ...
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Is it possible to make water steam batteries?

I have a few questions, What happens if we compress water steam? Does its temperature increase (Gay-Lussac’s law)? Or does it become liquid? Can we store the compressed water steam in a tank and use ...
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Does temperature in a vessel with same top surface area as a earthern pot and same amount of water have same temperature of water?

Many people answer the question 'why earthern pot keep water cool?' In this way 'Because it has large surface area that allow more evaporation than other vessels we used to keep, so more cooling.' But,...
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What is the experimental evidence that the gravitational constant $G$ runs with energy (or temperature)?

Various papers on quantum field theory claim that $G$ runs with energy, like the fine structure constant does. Some examples: Frolov, Fursaev and Zelnikov, Nucl.Phys. B486, 339 (1997) Volovik and ...
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Why water in earthern pot cools only upto some extent?

I have noticed that water cools in matka(earthern pot) and people give it as a reason of evaporation of water at pot surface and further conduction of heat of water to cool down pot. But evaporation ...
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Why pouring sanitizer on hand feel much cooler than water although both perform evaporation?

Which absorb more heat from hand? Sanitizer or Water? Both absorb heat from hand than why pouring sanitizer on hand make hand feel much cooler than rhat of water?
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Is high temperature a necessary condition for an object to be a blackbody?

A Light Emitting Diode (LED) is a semiconductor light source that emits light when current flows through it. Electrons in the semiconductor recombine with holes, releasing energy in the form of ...
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Picking an Aluminium temperature buffer size to match any given volume of water

It is common to use a temperature buffer of some kind to dampen down the the response time of a temperature sensor in many applications, like cold storage of vaccine and blood. The size of the buffer (...
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Why does hot air trapped in woolen cloth move away (rise up) and thus no insulation layer form?

We have learnt that hot air is less dense therefore it rises up. But we also learnt woolen clothes trap air that get warm by body heat, and act as a insulation layer dont allow heat to escape from ...
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Entropy change speed with induced heat flux density and thermally isolated system volume equation

I have a thermal conduction problem. The text reads as follows (i apologize, if my english is not good, I'm not a native speaker) A temperature gradient is generated in a thermally isolated system. ...
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Will water in a vacuum chamber become cold fast after being heated?

Imagine a vacuum chamber with: a glass container inside filled with water; a copper tube that penetrates a little bit in and a little bit out of the chamber and enters the glass container; After all ...
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Why does a fixed IR scanner sometimes measure my body temperature as ridiculously low consistently?

We have a fixed IR hand temperature scanner at work and sometimes on one day measures my body temperature as 24 degrees Celsius and it does several times in the same day. I have read on Thermos that ...
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Is it possible to make a plasma with high nuclei temperature and low electron temperature?

Because of the extreme differences between electron mass and nuclear mass, kinetic energy exchange between electrons and nuclei is very inefficient. As a result, a plasma with different electron ...
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Color Spectrum of Heated Metal [closed]

I have seen a few questions and answers according this subject. What troubles me, is that I saw somewhere that there is a difference between oxidation colors and incandescent colors when heating ...
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Calculating the Absorbed Heat & the Change in Internal Energy of an undefined thermodynamic process

In the given figure of a P-V diagram, the process from $T_2$ from $T_3$ (the hypotenuse part of the triangle) doesn't follow any of the 4 thermodynamic processes (i.e Isothermal, Isochoric, Isobaric, ...
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Amount of wood needed to cook rice [closed]

$\def\¿{\:\mathrm}$I am trying to estimate the amount of wood fuel used by household using 3 stone stoves to cook rice. These stoves have a thermal efficiency of 10%. I first calculated the energy ...
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Meaning of internal energy in the First Law of Thermodynamics

In my textbook, I have learnt that the First Law of Thermodynamics states $$ΔU = Q - W$$ where $Q$ is the heat energy applied to the system, $W$ is the work done by the system on its surroundings, and ...
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Accidental Gas Measurements in a Temperature Humidity Chamber reveal weird CO2 behavior

Accidental gas concentration measurements inside a temperature humidity chamber revealed the gas concentration levels inside the chamber changed significantly from known ambient atmospheric gas ...
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Does an expanding universe cool down?

I want to know if and why the temperature of an expanding universe decreases with time. Universe setup. My universe is modeled as the manifold $]0,\infty[\times\mathbb T^3$, where $$\mathbb T^3 = (\...
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How do you Find the Variance of Temperature in a Maxwell Boltzmann Distribution?

In Understanding Molecular Simulation, the following Maxwell Boltzmann distribution for momentum is given: $$\mathcal{P}(p) = \left(\frac{\beta}{2\pi m}\right)^{3/2}\text{exp}\left[\frac{-\beta p^2}{...
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Negative temperature and Absolute zero [duplicate]

Negative temperature and Absolute zero Below absolute zero This may sound more unlikely than freezing hell, but physicists have created an atomic gas with a temperature below absolute zero for the ...
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Why can the surface temperature of a star be calculated using the Stefan–Boltzmann law?

I calculated the surface temperature of the sun using the energy flux of the sun and the Stefan-Boltzmann equation, as is seen in the beginning of this post, but I am confused on how this gives the ...
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When we shrink a box containing a gas, does the increased frequency of molecule impacts on the box cause the rise of its temperature?

When we shrink a box containing a gas, does the increased frequency of molecule impacts on the box cause the rise of its temperature? I assume the kinetic energy of the molecules shouldn't change ...

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