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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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Need help explaining results of a frequency/temperature experiment for a ukuele

I recently performed an experiment for school which involved plucking different strings on a ukulele at different temperatures and measuring the frequency of sound produced. I expected to find a ...
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23 views

Optical deexcitation with energy higher than the excitation light?

Every line of the characteristic spectrum of an atom has not a perfectly defined energy (frequency), but a finite width (the higher the width, the shorter the lifetime of the excited state) right? ...
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1answer
35 views

Is there an equation for a solution's electrical conduction as temperature varies?

I'm looking for an equation that determines a solution's ability to conduct electricity as temperature varies, that hopefully could offer insight to a salt water experiment. I did an experiment ...
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18 views

Ideal gas assumption for the Temperature Jump Distance calculation

I want to calculate the contact conductance between two surfaces that have a thin layer of air (on the order of micrometers) between them. A quick literature review shows that the heat transfer ...
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0answers
37 views

statistical definition of the temperature, the thermal energy and the pressure for an non-ideal gas

I recently realised that my definition (and understanding) of the temperature was only valid for a ideal gas: $T=\frac{2}{3 k_B}\int (u-v)^2f(v)dv$ where $u$ is the mean (or global) velocity of a ...
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2answers
47 views

If efficiency is more important, then why condenser is used in boiler?

What's the real reason behind condenser? some says, Without condenser, back-pressure will be created in turbine. After Expansion in turbine, entropy will be maximum so it must be cooled to reduce ...
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49 views

Why does the sand start to increase slowly when shaking for a long time (first law of thermodynamics) [on hold]

Good day! I have a question. At first, the temperature of sand increases rapidly when we are shaking. However, why does the temperature starts to increase slowly when we shaking for a long time? This ...
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16 views

Why Mercury, Cadmium and Zinc has low melting and boiling points and elements next to them start melting at a bit higher temperatures?

I have been playing with online periodic table and noticed that melting/boiling points are lowest for noble gasses and non metals then it starts for metals on left and creeps from right side of the ...
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1answer
47 views

If an atom is in its ground state, has the atom the lower energy possible and there is its lower temperature?

"In the lowest energy state, the constituents of the atom (the nucleus and the orbiting electrons) are arranged so that the total energy in the system is minimal. This is called the ground state of ...
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4answers
56 views

How is work transferred to the system recognised?

For example, a potato initially at room temperature $25 \sideset{^{\circ}}{}{\mathrm{C}}$ is baked in an oven that is maintained at $200\sideset{^{\circ}}{}{\mathrm{C}}.$ I made potato as the system ...
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2answers
55 views

Life around a different element from Carbon [closed]

On Earth, life developed around Carbon (and Hydrogen and Oxygen). I guess this depends on the availability of those elements, but also on the spectrum of radiation and Temperature and Pressure. Under ...
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1answer
31 views

Specific Volume vs Temperature Graph

When looking at a graph of comparing temperature and specific volume, we see that for increasing pressures, the boiling point increases and that the length of the saturated liquid-vapor line decreases....
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2answers
111 views

What is highest possible temperature?

The Planck and maximum temperature In the Planck temperature scale, $0$ is absolute zero, $1$ is the Planck temperature, and every other temperature is a decimal of it. This maximum temperature ...
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1answer
38 views

Temperature Proxy (Climate)

At the bottom of the wikipedia article on climate proxies there is this formula: $$ \delta \, {\rm ^{18}O} = \frac{\frac{\left[\rm{^{18}O}\right]}{\left[\rm{^{16}O}\right]}}{\frac{\left[\rm{^{18}O}\...
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1answer
50 views

is boiling point of the gas cause cooling in expansion process of refrigeration?

I have a doubt about expansion process. Some people say it's an adiabatic expansion, but other say it's something related to the nozzle. What is the actual cause for cooling in expansion process? ...
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1answer
51 views

Is entropy lower at zero temperature or the Planck temperature?

I have already asked a question about entropy, Entropy and temperature, but I think this question is more pertinent and very different. It is said that object with very low entropy have a lot of ...
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0answers
30 views

How would the conditions be on the surface of very low mass black dwarfs? [closed]

How would the conditions be on the surface of very low mass black dwarfs? These would (will) be from very low mass stars and be formed of hydrogen rather than carbon, so presumably they'd be liquid ...
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1answer
18 views

How is the relation for variation of resistivity with temperature obtained?

The graph of resistivity vs temperature shows a fairly straight line plot over a long range of temperature. Now, let us plot resistivity in the y-axis and temperature in the x-axis. Now, in my book ...
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2answers
25 views

Direction of temperature gradient while studying thermo electric effects

What is the direction of temperature gradient, when we study about thermoelectric power. And what is exactly meant by up and down the thermal gradient?
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0answers
19 views

Cool a room with a fan, what sens orientation? [duplicate]

It is really hot these days, and at night, I try to cool my room before going to sleep but I'm wondering in which sens I should orient my Fan Answer A : Push the hotter air with my fan outside. ...
2
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0answers
54 views

Can the melting temperature of metals be altered by modifying the local electric charge?

I'm researching a project in which metal needs to be melted. It would be very helpful to be able to reduce the melting temperature to improve the feasibility of the project. I've been looking into ...
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1answer
63 views

Relation between The speed and Temperature of the molecule

I'm fully aware of Gay-Lussacs Law, but when I was reading Feynman Lectures on Physics volume 1, sir said that the temperature and the speed of the gas (Ideal Gas) are proportional to each other. But ...
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3answers
64 views

Max. air temperature on Earth [duplicate]

Is there any max. temperature that air on Earth could reach, assuming that solar radiation is standard and the average temperature on Earth is 14.6 like today? I mean, is there any chance that the ...
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2answers
34 views

O2 molecues speed in air, and their limit

Temperature is the proportional measure of kinetic energy of the random motion of the constituent micro particles in a system as per wikipedia. Now I understand that O2 molecules are randomly moving ...
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1answer
30 views

Planck law near absolute zero

Is the Planck law of radiation valid even for $T$ near absolute zero? Why can we be sure that the mean photon number inside a black body is zero for $T\to 0$?
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1answer
175 views

Temperature Required to give Particles of Matter Speed comparable to the speed of light

We know that at 0 K, particles of matter almost stop vibrating/moving completely. Also, as we increase temperature of the system, the particles gain energy (in the ...
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2answers
74 views

Global warming and air temperature

The layman's question. Is there a maximum temperature that can be reached by air on Earth due to global warming? For example, one that would prevent living organisms from functioning? I read somewhere ...
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2answers
48 views

What's happening if we vacuum an air that exists inside aclosed system?

Excuse me, I have a closed system and wanted to vacuum an air that exists inside it, so what is happening with temperature inside that system ? Is it increase or decrease ?
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0answers
27 views

Optimally cooling a cup of broth

Say I have a cup of broth with volume V1 and it's too hot to drink. I want to cool it down as quickly as possible. the current temp of the cup is T1 I want to drink the cup when it cools to T2 I have ...
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1answer
36 views

A question about temperature in the concept of a macroscopic statistical-mechanical system

I recently have come across a question while working on Statistical Mechanics. The question itself was quite straight forward (no this is not a "do my homework" question in case you were wondering) ...
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2answers
49 views

What causes the distribution of energy among molecules?

If every molecule were to start of with the same kinetic energy would it become a distribution of energy like the boltzman distribution and if so why? Is it due to inelastic collisions?
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0answers
31 views

How can austronaut survive in the Thermosphere? [duplicate]

In my college class on space.. it says that: Thermosphere's temperatureis about 2000C approaching 500 miles into space? This would basically melts everything we are using in our space crafts, the ...
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1answer
40 views

What is the exact difference between static pressure and temperature?

If temperature is the average amount of energy and static pressure is the amount of internal energy, wouldn't the static pressure be the same as the temperature?
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4answers
64 views

Does the pressure-volume-temperature realation of gases also work on solids?

I've read about the Combined gas law which said: The ratio between the pressure-volume product and the temperature of a system remains constant. My question is: Does this law also works on ...
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0answers
51 views

How does the temperature of water affect its refractive index?

I am aware this question has been asked many a time but i have never found a answer which satisfied my exact requirements. I recently completed an experiment on how refractive index is affected by ...
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3answers
49 views

Inferring past heat distributions from present heat distributions

Solving the sourceless heat equation with dimensionless variables $u_{xx} = u_t$ on a disk with $u(x,0)=f(x)$, one gets under suitable assumptions: $u(x,t) = \sum C_n e^{-n^2t}e^{inx}$, $C_n$ being ...
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2answers
45 views

egg in the bottle demo gas law identity

so, i've taught chemistry and physics for 15 years, and yet i still need help with this. the classic egg in a bottle demo i'm referring to is the one done with a lit object being placed in the bottle....
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0answers
31 views

No Temperature in an Expanding Universe?

The statistical definition of temperature as $\bigg(\dfrac{\partial \ln \Omega}{\partial E}\bigg)^{-1}$ inherently assumes the existence of a well-defined energy. To my understanding, a well-defined ...
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1answer
78 views

Assumptions made for Newton’s Law of Cooling

I am trying to prove the Newton’s Law of cooling equation - $$\frac{dT}{dt} = -k(T - T_a)$$ where T(t) is the temperature of the object at time t, $T_a$ is the ambient temperature, and k is a ...
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3answers
164 views

Dam Son's problem: how long does it take to boil an ostrich egg?

The egg boiling problem is a seemingly simple problem posted from the blog of UChicago's physicist Dam Thanh Son. A chicken's egg has a length of 5 cm and takes 6 minutes to boil. An ostrich'...
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3answers
56 views

Variation of degrees of freedom with temperature

I read in my friend's thermodynamics notes that polyatomic molecules have a different degree of freedom at high temperatures (viz. non-linear triatomic molecules have 9 dof but only 7 are accessible ...
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1answer
45 views

What will the temperature on earth be were it to stop spinning?

How hot will the lit part be and how cold will the unlit? This depends of course on latitude. Also if we take away the atmosphere will the situation be just like on moon? I talk about a situation with ...
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2answers
182 views

Blackbody radiations

The energy absorbed per unit time by the body at an absolute temperature $T_1$ and kept at a surrounding of higher temperature $T_2$ is $$J=\epsilon\sigma A T_2^4.$$ What my question is that aren't ...
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2answers
61 views

Room not getting cooled

I am in a room which is heated up duringg day, in night outside temp is quite low, but my room with a ceiling fan running still feels hot as it was in day if I step outside door its cold. There is ...
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1answer
65 views

Thermal equilibrium vs steady state

According to Kirchhoff's law, when two objects are in thermal equilibrium, both objects have the same temperature and each object emits as much energy as it absorbs. Also, the energy absorbed at each ...
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3answers
284 views

Stefan Boltzmann law and specific heat of a body

Consider a body (not blackbody) at temperature $T$ kept at surrounding of temperature $T_s$. Due to the temperature difference, heat will be lost from the body in the form of radiations from its ...
13
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2answers
2k views

Does shaking a water bottle increase the temperature of the water inside?

If I am at a cold place, can I warm a bottle of water just by continuously shaking it? If yes, how long would it approximately take, i.e., is it physically possible or just theoretically?
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0answers
27 views

Why does the change in momentum occur over the time taken to travel distance 2L?

In the derivation of mean square speed in thermal physics, the time taken for the change in the momentum of a molecule is equated to the time taken for it to travel double the length of the container, ...
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1answer
39 views

Is there a way to take energy from matter beyond 0°K and if yes, what would it do?

From my simple understanding, as you cool down a piece of matter, you take energy from it (neglecting the energy needed to cool it down). Is there a limit to this? Is that limit absolute zero (0°K) ? ...
4
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1answer
159 views

Why have all stars roughly the same order of surface temperature?

Given that stars vary in volume over 10+ orders of magnitude, why are they roughly the same order of surface temperature (emitting much of their radiant energy in the visual range of the EM spectrum)? ...