Heat transfer Definition and 875 Threads

If say the temperature of just one component of air e.g. water vapor suddenly rises (say through IR absorption), what method can be used to very roughly and quickly calculate the amount of time it will take for the temperature to even out?

1) A blackended, solid copper sphere of radius 4.0cm hangs in a vacuum in a enclosure whose walls have a temperature of 20.0 celcius. If the sphere is initially at 0 celcius find the rate at which the temp. changes assuming that heat is transferred by radiation only 2 questions: - do we...

1) a copper bottomed saucepan containing 0.8L of boilling water boils dry in 10min. assuming all the heat flows through the flat coper bottom, which has a diameter of 15cm and a thickness of 3.0mm calculate the temperature of the outside of the copper bottom while some water is still in the pan...

Thought this would be the most appropriate forum to ask for help Air flows through a copper inside tube and is heated by saturated steam condensing on the outside of the tube. 1. Determine the rate of heat transfer to the air at 3 different flow rates of the air (rotameter readings 10, 20...

I don't understand this problem. I think it is difficult for me. Please anyone suggestion this problem to me. Thanf you Let us cosider steady state heat transfer problem in which laplaceT(r)=0 What is the temparature at the center of a thin disc of radius a whose average boundary...

I want to simulate radiation heat transfer between two surfaces which are in the vacuum using FemLab3.1. However, the heat transfer module only consider conduction and convection. Some additional examples I found incorporate radiation (with surace-to-surface option) but they need a conduction...

The surface of the Sun is at approximately 5700 K and the temperature of the Earth's surface is about 290 K. What total entropy change occurs when 1000 J of heat energy is transferred from the sun to the earth? a. 2.89 J/K b. 3.27 J/K c. 3.62 J/K d. 3.97 J/K I don't know what formula to...

I'm reviewing a letter regarding the sheilding of an object using a superconducting magnet as is commonly found in MRI machines. The claim is that the magnetic field created by superconducting windings (wire which is carrying a current and thus creating a magnetic field) and wrapped around an...

I have a graph which shows the rate of cooling of a tent from about 35 deg C to 15 deg C, it looks like this: http://students.bath.ac.uk/en0jma/graph.gif How do I work out the convective heat transfer coefficient of the tent from this data? Thanks for any help

hey I'm wondering if someone can help un-stuck me on this question - I'm not sure if what I'm diong is right >< A crate of fruit with a mass of 31.0kg and a specific heat capacity of 3800 J/kg K slides down a ramp inclined at an angle of 38.4 below the horizontal. The ramp has a length of...

got a proplem that i just can't seem to get 200g of water is placed in a 80g aluminum cup and left undesturbed in a freezer until it reaches -5c the cup is then taken out and heated to 96c a. how much heat is needed to increase the temp (from the -5c to 96c) b. replace the alum cup with an...

Please don't beat me up too badly. I ask this in all sincerity. A very small device adds energy to a system primarily via radiation. Temperature differential is high—at least 1,500°F. The system itself is rather massive—tons. Intermediate heat transfer is via forced convection of a...

Hi all. I am doing some work with temperature equations. I have a book that gives an equation and then manipulates it. However, I can not follow what the author does, so can anyone help: He starts with: [FONT=Courier New]dT/dt = Q/MC - (T-O)/RMC (in the following I use the text...

I have a problem that I need to solve that is quite extensive it boils down to this. I have a steel vat that's been plated with zinc and its being used to store sulfuric acid. I have to find corrosion rates, heat transfer and thermal stresses, elastic and plastic deformation problems, hydrogen...

I'm having a bit of trouble with a Thermal Physics excercise. I was wondering if anyone knew what the definition of the heat transfer coefficient was? I can't find anything about it in my textbook (Thermal Physics, 2nd ed., C.B.P. Finn). More specifically, the assignment at hand says to find...

Hey People...um this is a question i got for school...i know what was used to solve it but i can't understand how that method was used and why they did that... it says: A foundry operator finds that it takes 55.3MJ of heat to heat a 286 kg mass of an alloy steel from 22 degrees C to 452...

Hello all, I am a little confused on this problem and want to be clear on it. Given: Water is boiled at 1 atm pressure in a 20-cm i.d. pan. Water level in pan drops by 10cm in 30 min, determine the rate of heat transfer to the pan. Now correct me if I'm wrong but water boils at 100...

I was just wondering if there's a word to describe the ability of a substance to lose heat to it's surroundings. Thanks, Jacob

I am lost on this homework assignment, and I am really hoping that you guys can help me out. Here goes: A 500.0-g Fe bar at 212 degrees C is placed in 2.0L of H20 at 24.0 degrees C. What will be the change in temperature of the H2O? (if is assumed that no heat is lost to the surroundings) I...

I'm going to attempt to articulate my question with appropriate lucidity, but please let me know if I fail to do so. I am a vintner (a wine maker), so achieving a palatable batch of wine necessarily elicits some required understanding of chemistry and physics. I understand that the wine...

lets say you have the following situation: you have a cold pool of water, and hot air outside. how do you calculate the rate at which heat is exchanged (given Twater and Tair, the surface area of the pool, etc.)? Now, let's say you add a layer of a certain material x meters thick that has a...

MIT is making available for download a genuine undergraduate textbook in Heat Transfer. This is an experiment to see how well this idea will work. http://web.mit.edu/lienhard/www/ahtt.html is the download.

I have some homework problems that I've been stuck on. Not sure if someone can point me in the right direction... 1) The temperature in an electric oven is 173 °C. The temperature at the outer surface in the kitchen is 39.8 °C. The oven (surface area = 1.51 m^2) is insulated with material...

During a cold Chicago winter, a steady thermodynamic state has been reached in a small pond with a layer of ice on the top. The air directly above the pond is at -7 oC and the ground at the bottom of the pond is held at 2 oC. The pond holds a total of 342.1 m3 of water and has a relatively...

Hi, Does anyone know the heat transfer coefficient (&lambda in W K^-1 m^-1) of oil. I'm looking for this for polyolester, but if you have data of another oil, tha't would be fine! Thanks, Smurfje