Thermal Definition and 1000 Threads

Need help on Thermodynamics problem: thermal expansion to be more specific! A steel ring with a 2.5000in- inside diameter at 20.0°C is to be warmed and slipped over a brass shaft with a 2.5015in outside diameter at 20.0°C. Part A: To what temperature should the ring be warmed? Part B...

Hey came across this question in my physics textbook. If the surface of a material is under compression, is it hot or cold relative to the body of the same piece of material? Unfortunately their explanation doesn't make any sense what so ever! Would anyone like to give an explanation that makes...

Homework Statement A heat engine using 110g of helium as the working substance follows the cycle shown in the figure. http://session.masteringphysics.com/problemAsset/1074114/5/19.P59.jpg What is the engine's thermal efficiency? Homework Equations n=W/Q_h The Attempt at a...

Homework Statement The brick wall of a building has dimensions of 4m by 10m, it is 15cm thick with a coefficient of thermal conductivity of 0.8 (Wm^-1C^-1). (a) How much heat flows through the wall in a 12-hour period when the average inside temperature is 20 C and the average outside...

Hi there, I'm going to couple WIMS & CITATION as neutronic codes with PARET as an thermalhydraulic code. Please let me know if there is any resources, papers or tips and tricks to do so. Thanks

i have to plan and design an experiment based on this outline: " excellent thermal conductors are also excellent electrical conductors" could i get any ideas please?

So we were studying about different types of heat transfers, conduction, convection, and finally we learned about radiation, it was sort of confusing, so I am going to write stuff, and hopefully someone can see what i wrote and see if its correct. basically the book says 'Radiation...

How would someone define thermal energy? My view is that it is the internal energy of the object e.g potential and kinetic energy. But from what I understand it can also be the energy transferred from one object to another, this is where I get confused. Dose the term thermal energy aka heat...

i need some conceptual help for my final year project... what are the thermal properties of ice cream?? Specifically the thermal conductivity and latent heat and the relation of it's variation with temperature... i'll be adding a copy of my abstract for better understanding. oh and yeah I'm a...

Homework Statement The following is a worked problem from my textbook: Consider two masses, with initial tempratures T1 and T2 are placed in contact and isolated from their surroundings. They are CV1T1 + CV2T2 = CV1Tf+CV2Tf This equation can be solved for the final temprature T_f =...

Homework Statement A brass rod's length is measured at 20.0 degrees C with a metre steel rule. The length of the rod is determined to be 0.5260 m. The measurement is repeated at 61.6 degrees C. Taking into account the expansion of the rule and rod, what is the new measured length in metres...

Homework Statement This question has got me REALLY confused. I'll be thankful for any help. I don't even know where to start, though I'll mention what my thoughts were. Q. A jeweller wishes to harden a sample of pure gold by mixing it with some silver so that the mixture contains 5.0% silver...

Homework Statement A well lagged calorimeter of mass 120g contains 200g of water and 50g of ice, initial at 0°C. A jet of steam is blown through the water until the water temperature reaches 30°C. Calculate the mass of steam that must condensed. The specific heat capacity of Copper...

A brass plug is to be placed in a ring made of iron. At 10°C, the diameter of the plug is 8.731 cm and that of the inside of the ring is 8.719 cm. a) They must both be brought to what common temperature in order to fit? b) What if the plug were iron and the ring brass? formula for...

hi, i don't quite know how to pose this question but i'll try my best. if you have an object and heat one end of it, energy will move from an area of high energy, to an area of low energy. By this method, heat transfer will stop when all regions of the object are at the same temperature...

[SIZE="2"]By a simple procedure , what should I do when I'm going through the thermal hydraulic design of nuclear reactor core...? .. I put initial guesses for the core dimensions ( fuel , clad , gap , length) initial guess for the fuel element pitch desired power ... I've found q'' critical...

A student suspects that the power rating on an immersion heater is 50 W but he is not sure.He sets up an apparatus as shown. After the liquid has been brought to its boiling point, he finds that 3.5g of vapor escaped each minute through the outlet tube.The boiling point of the liquid is 80...

I want to calculate the average thermal conductivity of UO2 by : 1/(To-Tf) * ∫To->Tf dT K(T) any one can provide me anything about the thermal conductivity of UO2 as function of temperature or any measured data in a range of temperature.

Hello, My apologies for making my first post a question but I was wondering if anyone could suggest an engineering degree which would be most suitable for a career with energy, specifically thermal energy and external combustion systems. I was technically a junior and had to take an session...

Hi, I need a way to convert kinetic energy into thermal energy as well as the specific heat of the entire Earth's atmosphere. The idea is to see if the heat generated by many meteoroid fragments could possibly account for any climate change. Thanks.

Postulate a parcel of air within the larger atmosphere. The air above the parcel is cooler than the parcel, while the air below it is warmer. The parcel is emitting photons to both the overlying and the underlying layers of air and simultaneously absorbing photons from both layers. Both sets...

It's not really homework, it's more of my own testing of a hypothesis, but I don't really know where else to put it. I need a way to convert kinetic energy directly to thermal energy as find out how much thermal energy it takes to raise the temperature of the atmosphere 1 degree, or I guess...

I learned that solids conduct heat by vibrating and thus transferring the energy from one particle to another particle. However, my teacher gave us a question: two metal rods of different material are placed in a fire. one of them turns red hot at the end while the other remains silver coloured...

Homework Statement I'm reading Kittel&kroemer's Thermal physics. How can I know Entropy's functional dependency? Author assume entropy's functional dependecy without explanations and derive some equaltities. So I can't follow it. N the number of particles. U Energy of the system. V. volume of...

In the proof that I have studied, there is a Isothermal cavity that behaves as a black body. there is another small opaque body inside the cavity at the same temperature with emissivity e, absorptivity a and area s. now the irradiation on the small body is Eb = σ times T raised to 4. now the...

This isn't a HW problem - I am just having a hard time following one of his examples. On page 47 near Eq. 1.71 he says "As a quick example, consider a drop of food coloring added to a glass of water. Imagine that the dye has already spread uniformly through half of the glass. How long would...

So I am doing a second year thermodynamics course and would like to know. Do we just have to remember (5/2)PV for a diatomic gas, why is it 5/2 and also what is it for a monatomic gas. Also would we have to remember more complex ratios for exams? Cheers

Homework Statement During the game, the metabolism of basketball players often increases by as much as 30.0 W. How much perspiration must a player vaporize per hour to dissipate this extra thermal energy? Assume that perspiration is simply pure water and that perspiration starts at...

Hallow! For real it's not clear to me on how the thermal voltage in a semi-conductor is established... Can anyone help?

The above diagram shows the problem description. I have to find the final temperature distribution after thermal equilibrium. I am assuming that the thermal energy is conserved but not the temperature.(Correct me if I am wrong) Energy of the materials at initial state is (Refer Image) For...

I searched for something relevant and came up short so forgive me if there is already a thread started on this. I am taking a heat transfer class right now and am trying to figure out a few things. My question arose when going over thermal resistances and how it relates to the general...

Hi guys! I think I need to explain myself before I ask for the advice :) I'm 27 (so been in grade 12 ages ago) - I didn't have science, I wrote it years later. Now I'm enrolled for a Bsc degree in the hope of getting into medical school (very tough in South Africa). I'm putting a lot of time...

Homework Statement Air is mostly composed of diatomic nitrogen, N2. Assume that we can model the gas as an oscillator with an effective spring constant of 2.3 x 103 N/m and and effective oscillating mass of half the atomic mass. For what temperatures should vibration contribute to the heat...

Hi. I'm reading an introductory section on the Bose-Einstein condensation of a non-interacting, spinless boson gas. I'm confused by the claim that the ground state is in a coherent state with eigenvalue sqrt(N0) exp(i theta), where N0 is the expected number of particles in the ground state. The...

Hello, I'm looking for some feedback on and an analysis of a spreadsheet calculator I've made. It looks at temperature changes over time, given starting volumes of a building shell and thermal mass. The calc takes into account building fabric and ventilation heat losses. First I've...

Hi I've been trying to find effective thermal conductivity of sintered bronze, especially of that used in self-oiled sliding bearings (like Oilite). I need it to know how much less it is compared to dense copper alloys, eg. tin bronze. So far my search has proven fruitless. It seems that...

Homework Statement So you have a fridge, the walls of the fridge are made of aluminum, plastic and insulation. Which is the most relevant and why for the fridge. Homework Equations Thermal conductivity of aluminum=250 Plastic=.03 insulation=0.035 - 0.16 The Attempt at a Solution...

1. Star X has a surface temperature of 10,000 K. How much power does it emit per square meter? Enter numbers only. Do not enter units (watt/m2 is assumed) 2. Star X has a surface temperature of 10,000 K. What is the wavelength of the dominate electromagnetic radiation that Star X emits? Enter...

Are there any major questions yet to be solved in these fields? Also where exactly does thermodynamics, heat fit into physics?Thermal Physics?

Homework Statement So the outside of a refrigerator is made up of plastic, metal, and insulation? Which is the most important and why. Homework Equations no equation needed. The Attempt at a Solution I thought that the insulation would be the most important because it reduces...

Hello all I am trying to measure material displacement using measured thermal data.7 While the specimen is heated up, I want to measure how much it changes its length at particular points. Is this possible? If you have any further questions or suggestions please do not hesitate to...

Homework Statement I was wondering why there is such a disparity between thermal conductivty and how they act in the real world. Ex. If if have 3 cups filled with hot water. The 3 cups are made of glass, plastic and metal. The metal will obviously have way higher thermal conductivity...

Homework Statement I ask this because my initial assumption was that work done by a non-conservative force (friction in this case) is also equal to thermal energy. However, in my book, it gave an equation with W = Emec + E thermal. They also had an example where they added up the work and...

Homework Statement In a reactor, we're making 56Mn by inducing thermal neutron capture. 2g sample of 55Mn is put into the reactor which has a flux of thermal neutrons of 3E13 neutrons/cm^2*s Sample is in the reactor for 8 hours and then removed. a. Calculate the amount and activity of...

[b]1. Determine the volume occupied by a 1 mole of an ideal gas at 27° C and 1 atm pressure. Ammonia gas at 27° C and 1 atm is passed at a rate of 41 cm3 s-1 into an apparatus where it flows over an electrically heated wire of resistance 100 . When the heating current is 50 mA the gas leaves...

An ionic compound is more thermally stable when the metal cation is more reactive. So its harder to decompose. But then what's the difference between melting and decomposition? Also, when an compound is harder to decompose, does it mean its melting point is higher? Because even though Na2O...

Hi, I have been asked to determine the stress in a bar which has a diameter of 50mm when the temperature changes from 20 C to 50C. That's the first part. Secondly, I need to then answer whether or not the stress will be sufficient enough to raise a constraining load of 40 tonnes. Young's...

I was hoping someone could help me with a project I am doing. I have contacted a manufacturing company thatmakes thermal wrap material, and I need to see if this will work for my project. According to the manufacturer the material is 1/16" thick - this info was also given to me by the...

Homework Statement A certain metal has a coefficient of linear expansion of 2.00 × 10-5 K-1. It has been kept in a laboratory oven at 325°C for a long time. It is now removed from the oven and placed in a freezer at -145°C. After it has reached freezer temperature, the percent change in its...

If I have an object say a 1kg lump of metal. it is at a temperature of say 20c. I then take that object and raise it and place it on a shelf, does it lose any thermal energy due to the new height, In other words does it cool down for no other reason than being raised to a different elevation...