Thermal Definition and 1000 Threads

I was reading a book, 'Introducing Quantum Theory' by J.P.McEvoy, and I find it difficult to understand in details of Maxwell Distribution, Thermal Equilibrium, Fluctuation, Wein's law and Planck's quantum theory, so I am finding it difficult to follow Einstein's explanation of photoelectric...

Homework Statement A coffee machine in a café passes steam at 100°C into 0.18kg of cold coffee (s.h.c. the same as that of water(4200j/kg/K)) to warm it. If the initial temperature of the coffee is 14°C, what mass of steam must be supplied to raise the temperature of the coffee to 85°C Homework...

Hello.. The query is regarding thermal conduction of heat from a solid body: Suppose we have a long metallic rod which is insulated on the curved surface and one of the bases. If we supply Q amount of Heat for a small time to the rod from the non-insulated end, initially the temperature of...

Hello everybody, I am solving a 2D problem of thermal stresses in a rectangular plate in which temperature is changing only y direction. Plate has fixed displacement conditions. Could anyone help me to find out analytical solution of thermal stresses for my problem? Does anyone suggest me...

Homework Statement A 1.0 sample of nitrogen gas (diatomic)is heated at constant pressure from 300K to 420K, Cp (nitrogen) = 29.1 Jmol-1°C-1 The thermal energy transferred to the gas is? 1. 8370 J 2. 12,200 J 3. 34.90 J 4. 3590 J 5. 12.20 J Homework Equations KE = 1/2mv2 =...

Consider a 47000K object that emits thermal radiation. How much power does it emit per square meter? What is its wavelength of peak intensity?What formula do I use to solve these questions?

I'm currently having a bit of an intuitive problem understanding the Prandtl number effect on boundary layers and I'm hoping that someone can explain it better than what I've read in some heat transfer books. According to various HT books, a low Prandtl number means that heat diffuses quickly...

So I have to write out nodal equations for a system that I was given, and I started off by drawing out the flow diagram to see where everything was. I'm having trouble starting the nodal equations though. The attachment has 2 diagrams: figure 1 is the correct diagram that models the thermal...

Hi Everyone, Does anyone know of a tool that can extract thermal neutron cross-section data from endf for all availible isotopes? I'm trying to help my professor compile some data to modernize one of his courses. I'm trying to find a list of capture and scattering cross-sections for a wide...

Homework Statement A container is divided into two parts by a thermally conducting wall. There are N atoms of a monatomic ideal gas on the left side, 2N on the right. The gas on the left is initially at absolute temperature 200K, the gas on the right at 500K. a. After thermal equilibrium...

Homework Statement A non-isotropic material is heated, fractional increase in length is different along different directions. With length l1=6.1 cm and l2=6.0 cm. In direction of l1, the coefficient expansion is \alpha1= 10×10-5 K-1 and direction l2 is \alpha2= 40×10-5K-1. The plate is heated...

Homework Statement (B) http://imgur.com/VL4aG although I showed the rest of the problem for context if needed Homework Equations ΔL=αLΔT The Attempt at a Solution I'm a little confused by the wording of the problem. When we find the shift in ΔN, are we actually finding Δ(ΔN)...

Homework Statement In an experiment, a small radioactive source must be moved at extremely slow speeds. A positioning device based on thermal expansion was devised where the radioactive source is attached to one end of an aluminum rod and a heating coil is wrapped around a selection of the rod...

Homework Statement Two cars collide head on while each is traveling at 80 km/h. Suppose all their kinetic energy is transformed into the thermal energy of the wrecks. What is the temperature increase of each car? You can assume that each car's specific heat is that of iron. Homework Equations...

A couple questions: I'm in the process of making some small amplifiers and using bjt's in the small signal realm. I have used bjt's as switches for quite a while, so I am quite familiar with their basic operation. I was reviewing small signal analysis trying to refresh my memory about how...

IF I am in error, forgive me. but I had this thought cross my mind today. IF absolute 0 is the stopping of all atomic (or molecular) movement. and you induce a thermal reaction, i.e. splitting the nuclei. would the reaction be slowed down at all? (to make a slow burn) Yea. I understand...

Homework Statement Show that at constant volume V and temperature T but decreasing number N=n*N_{A} of particles the Van der Waals equation of state approaches the equation of state of an ideal gas. Hint: Rearrange the equation of state into the explicit functional form P=P(v,T) and use x=1/v...

I had a thermal conductance homework problem where heat flowed through gold, and then silver. Both materials were of the same length and same cross sectional area. The problem mentioned that the energy transfer had reached a steady state, and I found through doing the problem that under these...

Homework Statement A set of telephone lines is to be installed so as to connect town A to town B. The town A has 2000 telephones. If each of the telephone users of A were to be guaranteed instant access to make calls to B, 2000 telephone lines would be needed. This would be rather extravagant...

Homework Statement A number is chosen at random between 0 and 1. What is the probability that exactly 5 of its first 10 decimal places consists of digits less than 5?Homework Equations Binomial Coefficient = \displaystyle \binom{N}{n1} Where n1 denotes "n1" objects of an indistinguishable type...

Hi all, I have a heat sink for which I know the exact geometry (have the CAD model). This heat sink was custom designed and machined from a hunk of aluminum, though it is very basic and I have a hunch I can find an extrusion or OTS part that will match its performance. Rather than trying to...

A vertical cylindrical container contains some helium gas that is in thermodynamic equilibrium with the surroundings. The gas is confined by a movable heavy piston. the piston is slowly elevated a distance H from its equilibrium position and then kept in the elevated position long enough for the...

in refrigerators, why cooling boxes are kept at top?

in winter, wooden floor feels cold to the barefoot but the rugs and carpets don not feel cold although the floor and carpet are at the same temperature?

Just a quick question relating to thermal equilibrium between a hot and cold body. If a hot body and cold (closed systems) are opened up to each other, the thermal energy will be transfer from the hot body to cold body through conduction. So even when thermal equilibrium is reached, the...

Suppose we have two separate containers of helium gas in thermal equilibrium and completely isolated from the rest of the universe. Let's assume the containers are ideal in the sense that they are completely tranparent to all electromagnetic radiation. Since helium is monatomic, the only...

What properties of an inductor change in a low temperature environment. Specifically in the -100 through -70 degrees Celsius range?

Hi guys, I'm having a bit of trouble with following thermal equilibrium question... Homework Statement Create an equation representing energy transfers of thermal energy equilibrium, that will enable one to determine the latent heat of fusion for ice. One conducts an experiment mixing ice...

\inthi all, I need just little bit of confirmation about what I'm doing. Normally I know how the stiffness matrix is composed for 2 node frame element in 3D space. which creates 12x12 matrix for that element, if there is also thermal loading on frame element additional...

Homework Statement I am working on this ahead of my fall class and don't actually want the answer... just pointers to help me understand something.. Thanks guys! :) I am really rusty with my general physics and calculus knowledge =( The original question asks me to prove that, for a...

If I sleep on copper would there be any beneficial release of negative Ions to improve my well being. In addition, will the thermal properties of copper stabilize my body temperature at 37.5c.

I just want to ask a simple question to experts here. Can superheating of steam increases efficiency and output of thermal power plants?

Homework Statement A hole in an aluminum plate has a diameter of 1.178 cm at 23 degrees Celsius. (a) What is the diameter of the hole at 199 degrees Celsius? (b) At what temperature is the diameter of the hole equal to 1.176 cm? Homework Equations The coefficient of linear expansion (α)...

Hey Guys, so I had a longish discussion with colleagues and on reddit about thermal equilibrium and the sun and how you cannot heat up anything above the surface temperature of the sun using clever mirrors and stuff. However, somebody came up with Napkin calculations of the Stefan Boltzmann...

Trying to model a thermal contact between two faces. The plan is to get the heat flowing from the right part to the left part with a temperature BC on the right and convection on the left. At the moment the left part stays in the initial temperature so the contact obviously doesn't work. I...

Does anyone knows any thermal insulation material which can be used for use upto 1500 to 1700 degree Celsius?

1.Homework Statement . Can someone give me more accurate mathematical models on thermal expansion? for example, linear expansion. 2.Relevant equations L=L0(1+α∆T) this equation is not accurate. for example. When an object 100m long at 0oC (example: aluminum, α=2.4x10-5) is heated to...

Homework Statement I only know volumetric expansion and linear expansion which require the coefficient constants that are not given in the problem. I also read somewhere that the mass remains constant during thermal expansion or is this false? The problem is attached pls take a look at it...

Hi, i'm searching for a material with the following properties: - high stiffness - low thermal conductivity - temperature resistance up to 150°C (not getting too soft at 150°C) - no low friction coefficient (so no PTFE) - good fracture behaviour (so no glass, ceramic) - cheap I've...

This isn't homework, so i thought it could go here. 1) What has thermal energy but not heat? 2) What has heat but not thermal energy 3) What effects angular momentum?

How can I figure out how to calculate the heat/cooling exchange rate of water inside pex tubing? I want to build a ground source cooling system simular to a chiller system but I want a closed loop system. My game plan is to pump ground water into a holding tank that is constantly flowing ground...

My editor friend is questioning the following passage in a book. Does this sound right? In particular, they seem to be making a distinction between "heat energy" and "thermal energy".

I have some car engine related questions, but basically just physics. -Do different specific heat capacities have anything to do with how certain materials resist heat? I know that on some engine compartments there is gold wrapping because it resists heat best, but it has a low specific...

Homework Statement determine the thermal effieincy of a heat transfer process where the following data has been used Input=3kW 1.7 litres of water have been heated from 313K to 375K in 2.5 minutes specific heat capacity of water= 4.19kj/kgK Homework Equations Thermal efficiency=...

I am trying to determine the expected heat exchange between flowing ground water in gravel/clay soil (that runs on top of blue clay) and glycol fluid in plastic pipe (1 1/4"). For my current interest, estimated ground water temperature of 60 degrees seems best. I am trying to determine the...

Hey there. We are struggling with a problem from an old exam about statistical mechanics. I hope you can help us or give any clues. Here is the problem. Homework Statement A chamber is divided by a wall into two sections of equal volume. One section of the chamber is initially filled by an...

Microwaves heating is often referred to as dielectric heating, but I'm not sure why this seems so special to specify of all the different thermal radiation frequencies. Doesn't infrared heat the dielectric material as well in a similar process? Isn't radiation heat transfer common for a wide...

Does it indicate that the " spooky action(correlation)" even can be found in classical level, where entanglement is hardly can be built?

Homework Statement Dry steam is used to make a cup of coffee by bubbling it through water. If the steam is at 100°C, what mass of steam must be used to heat 200 g of water from 25°C to 95°C? Homework Equations Not quite sure but I think: Q= mCΔT Qcold=-Qhot The Attempt at a...

I recently inherited a problem related to temperature measurement. Thermcouples (d- and k- type) are being used in a high-pressure, high-temperature environment, with the measuring junction suspended in an electrically-insulating solid. The leads of conductors A and B extend out of the...