Temperature Definition and 1000 Threads

In another thread I made this comment - My own reasoning says that without any heat exchange - without any cooling or heating affecting it - the temperature will remain uniform. I also expect that any such heating or cooling will have to be below a threshold - be too weak to cause an...

[ I think I should have asked this many years ago when I was studying !!! However it will help me re-understand thermodynamics and entropy a bit, and may be good for others on the same path so... ] Considering two portions of a liquid. Container A liquid is at a high temperature, container B...

Huskies are designed for snow and are much happier at -10 C What I can't understand is how they can tollerate living in houses at +25 C when the only way they can efectivly lose heat is by evaporation from the mouth , why arn't they constantly panting.

I searched the internet for the topic but I did not find an answer or a reference. * (Note): This is not a university assignment, but from the elementary class.

(a) ##T_{a}(t)=t+5## (b) $$\frac{dT}{dt}=-k(T-T_{a}(t))$$ $$\frac{dT}{dt}=-k(T-t-5)$$ $$\frac{dT}{dt}=-kT+kt+5k$$ Is my working for (a) and (b) so far correct? Thanks

From the van't Hoff equation we have $$\ln{\left ( \frac{K_p(T_1)}{K_p(T_2)} \right )}=\frac{\Delta H^\circ_{rxn}}{R}\left ( \frac{1}{T_2}-\frac{1}{T_1} \right )\tag{1}$$ So for ##T_2>T_1## we have ##K_p(T_1)<K_p(T_2)##. which is to say that the equilibrium constant increases for the higher...

where I live, the temperature varies between 33-35C and humidity ranges from 57-67% without rain, and I have electronic devices manufactured in the early 90s. What is the maximum possible interval for me to energize these all devices and for at least how many minutes to prevent failures in the...

Say I drop the pressure in a pipe from P1 to P2. I know T1. How would I calculate T2? When you expand the gas the temperature will drop, but there is also heat addition which will raise the temperature a certain amount.

My wire is 16 AWG (264 cores of 40 AWG) with 0.010 FEP Insulation. I have the insulation and the MJF nylon that it is touching melting! How much current would I need to have to get to these temperatures with this wire? This wire is inclosed inside the MJF nylon case, so figure for no air flow.

Is there a temperature-change equivalent to the speed of light?

The question is in the title. I'll just repeat it, is it theoretically even possible to have an operating superconductor at 25 celsius degrees? What is the theoertical threshold temprature that beyond it the superconductor doesn't function as such?

The steam in some saunas feels much harsher, hotter, burning or 'biting' than in other saunas. The sauna temp is the same at 90°c, pressure is the same or very similar. The amount and temp of water used is the same or similar. The only obvious difference is that the with the harsher feeling...

I make custom cast bronze decorative motorcycle parts using lost wax investment casting. I'm looking to improve the precision and reliability of my casting process (currently getting maybe 25% duds over time). My current initiative is to improve my temperature control on the shells prior to...

I've attached all my work and data table I used to answer the questions but there isn't an answer key so I would like a second opinion. a) The initial specific internal energy is.......Btu/lbm b) The initial mass is....lbm c)The average enthalpy of the withdrawn vapor is.....Btu/lbm d)The final...

I have stored here electronic devices with aluminum electrolytic capacitors used and manufactured in the early 90s. Here the temperature varies between 33-35C. These electronic devices need to be energized what time and frequency to prevent failures in these aluminum electrolytic capacitors...

and the solutions: I am not sure why two of the bodies are at the same temperature to end with. I am pretty certain that they don't have to be - but the author of the problem set it this way for some reason I'm missing (my guess). My reasoning: Put 100 K and 300 K together for a short time...

The total variation of internal energy states ##\Delta U_{tot} = 0## ##\Delta U_{tot} = \Delta U_{ext} + \Delta U_{gas} + \Delta U_{obj}## with: ##\Delta U_{ext} = Q_{ext} - W_{ext} = -W_{ext}## ##\Delta U_{gas} = Q_{gas} - W_{gas} = Q_{gas} - ( - W_{ext} ) = Q_{gas} + W_{ext}## ##\Delta U_{obj}...

Hi! I was wondering if it is possible to calculate the temperature near the roof of combustion chamber based on thermocouple reading which is located at nine o'clock position. Tip of measuring device is located 49 mm from the surface of hot face material. Please find the picture attached...

I wanted to find the differential form of the above equation and i get $$\frac{dR(t)}{dt}=R_{0}\alpha$$ (##t_{0}##=0 degree celsius) So $$\alpha=\frac{dR(t)}{dt} \frac{1}{R_{0}}$$ (##\alpha##= temperature coefficient of resistance ##R_{0}##=Resistance at temperature 0 degree celsius) This idea...

Do adiabatic processes maintain temperatures? That is, can temperatures remain constant during adiabatic processes?

I was going through the textbook Thermodynamics and an Introduction to Thermostatistics by Herbert B. Callen, and in Chapter 2.4 of the book, the author proves that given two subsystems separated by an impermeable and immovable wall which only allows for the transfer of heat, the temperature of...

Qmelt, honorite = (m honorite)⋅(Lfusion, honorite) Qmelt, honorite = 4.51kg⋅15500J/kg = 69905J Qcool, odium = (m odium)⋅(Cliquid, odium)⋅(391.14K−331.44K) Qcool, odium = 14.69kg⋅431.1J/kgK⋅(391.14K−331.44K) Qcool, odium = 378071.6823 Qfreeze, odium = (m odium)⋅(L fusion, odium) Qfreeze, odium...

Cooling Lerasium to its melting point: Q1 =m L⋅c L,liquid ⋅(T L,i −T L,melt) Q1 = 1.49kg⋅221.6J/kgK⋅(1108.1−56.4)K Q1 = 330.184 ⋅(1051.7) = 347254.512 J Heating Atium to its melting point: Q2 =mA⋅cA,solid ⋅(TA,melt −TA,i) Q2 = 2.44kg⋅524.8J/kgK⋅(308−33.6)K Q2 = 1280.512⋅(274.4) = 351372.493 J...

i am looking for a chemical compound that has a boiling or condensation temperature between 10C and 50C at standard pressure and is not one prohibited for discussion in the Physics Forum or any online chemical forums. something that is organic and not very toxic is preferred. it should be...

It’s been said that an air compressor could be “idealized” as a reversible adiabatic process in which case calculating the properties of the gas at the exit would be simple. The problem is, it rarely seems to be the case, in practice, that the process is reversible so how useful is this...

So first I used the ideal gas law formula PV = nRT to find n using P = 101000Pa, V = 1.81m^3, R = 8.314 J/mol*K^-1, T = 24.3+273.15 = 297.45K. I got n = 73.922 mol. Then I used P = density*g*h and found P = 2132.48 where density = 2560kg/m^3, g = 9.8 and h = 0.085m. Then I found total pressure...

I have a GE refrigerator( side by side ) about 11 years old now. I noticed warm milk yesterday. The set points for the freezer/fridge are 0 F and 37F respectively, and the actual temps are -7F and 55F. It seems like the freezer is running constantly, and the fridge side can get a word in...

Many years ago, I was a student in a HVAC program at a technical college. Sometimes when I and the other students were recovering refrigerant out of an air conditioner into a recovery tank, we would get ice from the ice machines and fill up a tub with ice, and then we would put the recovery tank...

Suppose there was a 4th generation of neutrino (X, say) with mass m ~ 1 keV. The other three neutrino generations decouple at T ~ 1 MeV and are not heated during ##e^{\pm}## annihilation (whereas the plasma is heated, leading to a bookwork ##T_{\nu}/T_{\gamma}## factor due to conservation of...

The translated version is: 1. 2. I did research on the topic and the Eötvös rule, but most of the results are just qualitative explanations or experiment-based proofs of the temperature-dependent function of surface tension. Can anyone give me some hints on how to prove that linear...

So, non-quartz sand has 1/2 mm kernels, they can be seen as individual objects from about 60cm distance. Standing in front of it, about a half of the individual sand kernels beam each separately into your pupil, so 500,000 discrete beams, each covers almost the entire pupil. Yet, you see a...

I am not sure if it is right to ask this question or not. Kindly let me know if it isn't. Actually I was going through the article Shadow Thermodynamics. I was trying to recreate the image fig 5 and 6 in mathematica. The idea is that we have to draw circles of radius ##r_s## given by equations...

Hello, I am a high school math teacher and recently presented my students with an intriguing problem: "At any given moment, there are two antipodal points on Earth (180 degrees apart) that have the same temperature." This can be demonstrated using one great circle with two opposite points. If...

I got this from chatgpt: It says "not simple and straightforward", but can we assume proportional ? So is there a visible alteration in Snell angle ? Also, for applied physics databases, what would be a pubmed equivalent, hosting all titles and synopses ? In physics the articles seem to be...

The notes my lecturer has provided state that the maximum temperature can be found taking p = 0 in the inversion curve formula, given as: I’m not sure how to obtain this?? These are the formulas: This is my attempt at a solution : Not sure if this approach is right?

Q=m.c.DeltaT, is one approach which could possibly give the relation between Power vs Time. Is it correct ?

Quoted from the O&M manual of an electrical steam superheater: "The Steam Superheater has eight thermocouples of the NiCr-Ni type, known as "K," attached to the heating element sheath. Four of these thermocouples are positioned near the steam outlet nozzle, where the highest temperature is...

From the graph: $$lnR(T)=\frac{-lnR(0)T^2_○}{T^2}+lnR(0)$$ I have assumed ##R(0)## to be the value of ##R## at ##1/T^2=0## and ##T_○## to be the value of ##T## at ##lnR(T)=0## From this I get, $$R(T)=e^{lnR(0)×\left(1-\frac{T_○^2}{T^2}\right)}$$ $$R(T)=R(0)^{\left(1-\frac{T_○^2}{T^2}\right)}$$...

Hello ! According to what I have read on the internet, the weight of a body varies with temperature, its mass remaining unchanged according to the theory of relativity. My question is what experiment is done to corroborate that the weight of a body increases with the increase in its...

I read that the solar wind is a stream of particles, primarily electrons and protons, flowing out from the sun at speeds as high as 900 km/s, and at a temperature of 1 million degrees. Using the equipartition theorem, I calculate that a proton moving at 900,000 meters per second exhibits a...

Is there a formula to calculate the speed of propagation of sound waves through steel (a steel bar, for example) according to the temperature of steel?

Hello guys, [FONT=arial]I am currently running an experiment in my hobby room: I want to heat a cube in a microwave and then measure the surface temperature. Unfortunately, it takes about 20 seconds, so the cube cools down during this time which means I don't measure the actual temperature...

I have been searching for the answer yet – as I'm here – didn't find it. The current model of climate warming says the lower parts of Earth's atmosphere don't allow the IR radiation to escape freely to the outer space because the GH gas molecules keep absorbing it virtually as soon as it's been...

Say there was something that made the temperature of the universe almost absolute zero, but around you was a mini bubble where the temperature was normal, and therefore molecules could move normally around you for a small area. How would you perceive the world around you outside of the little...

How to incorporate deviation -9.2C in furnace, while its measured temperature is 909.2C and Display temperature is 900. if there is no option of offset in controller. What will be the set temperature to achieve 900C.

Hi all, recently I started following the MIT course "Statistical Mechanics I: Statistical Mechanics Of Particles" by MIT (here). In the second lesson Prof. Kardar introduces the concept of thermodynamic temperature analyzing the behavior of two Carnot engines that share a thermal reservour at...

(a) (b) Here is a plot of this function T of R It seems that as the resistance goes up the temperature goes down. Not sure what to make of this physically speaking. My question is about the requested log-log graph. Above we have a function T of R, but we want a function ##\log{T}## of...

Could someone provide an ainformation what is the temperature inside the Large Hadron Collider (or similar systems) where the colision of particles happens? THANK YOU!!!!

Here is the table As far as I can tell what we have here are four constant-volume thermometers (each column represents a thermometer). These thermometers work by having a certain constant volume of some specific gas in a bulb. We immerse the bulb in whatever temperature we would like to measure...

Considering the approximation of perfect gas, I don't understand why at higher altitude the temperature is lower. Intuitively it is clear to me, but I do not understand the kind of transformation that takes place; the gas is free to expand and the pressure too is not constant, since it decreases...