Insulation Definition and 128 Threads

Hi. I am not in any way proficient in thermodynamics, but I was thinking about insulation and heat transfer and a few questions occurred to me. Since insulation blocks heat transfer, shouldn't a winter coat block heat in a hot climate? If you could only choose between wearing almost nothing...

Homework Statement The ceiling of a single-family dwelling in a cold climate should have an R-value of 25. To give such insulation, how thick would a layer have to be if it were made of each of the following materials? (a) polyurethane foam (thermal conductivity k = 0.024 W/m · K)...

So, I have a HiPot tester with a minimum capable voltage of 100VDC. I'm testing for any leakage between a string-pot and the housing case for the unit it goes into, with the requirement being 45VDC applied to it. With the HiPot tester incapable of supplying a voltage that low, I am thinking...

Sorry for such a simple question, but what are the differences between using insulation and heat reflective material? What is the effective of using them together? In my case I want to shield flammable foam insulation from melting or catching fire from a nearby heater. Will covering the...

some Fusion power experimental reactors use tokamaks to contain plasma using strong magnetic fields. However this plasma is at a sizzling 1M Kelvin so how is this level of thermal insulation engineered, using magnetic fields?

For current fusion technology the method for containing the plasma is with magnetic fields. However the plasma reaches temperatures of 100,000 degrees+ that would melt anything on Earth - so how do these super concentrated magnetic field provide thermal insulation?

I have been studying how electrical conduction and insulation works but have a few things I would like to get cleared up. Thanks in advance for any help. 1. Why is the energy needed for an electron to jump to the conduction band in a material so much higher in insulators then conductors and...

Hey, i am new to the forums and i have a question. I wouldn't consider this to be home work, because it is worth 10% of my first year score grade in physics. So it is a course work. I have to do a 10 min presentation on a material of my choice. I chose to do space shuttle tiles. So i was...

what is Rated insulation voltage for relay? On the catalogue of a relay, it says "Rated insulation voltage (Ui) V 250 (IEC), 300 (UL, CSA)" it doesn't say its AC or DC. it also says "Dielectric strength (rms voltage) Between coil and contact a V 2500 Between poles a V 2500...

So I go backpacking, often in winter. After a while you start to get interested in weight (since you are carrying everything on your back). I bought a kitchen scale and weighed everything, this showed some surprising results. I was thinking though, and if I am comparing two shirts and one is...

I live in a very hot climate. I have upgraded my windows to double pane thermal with some some success in cooling my home. I have been considering both additional fiberglass insulation and a radiant heat barrier for my attic as the air conditioning bill is still horrific and rates keep rising...

Homework Statement A house has well insulated walls. It contains a vol of 100m^3 of air at 300K a) calculate the E required to increase the T of the diatomic gas by 1.00C b) If this E could be used to lift an object of mass m through a height of 2.00m what is the mass of m? Homework...

So I've been curious about thermal conductivity lately, and came across a good reference that showed the conductivity of various materials. http://www.engineeringtoolbox.com/thermal-conductivity-d_429.html It says that air has very poor thermal conductivity (in other words, it acts as an...

hello! how do we calculate the thickness of insulation (wool) material to be used for a boiler. thanks

1. for fluids,why is the specific heat capacity at constan pressure is greater than that at constant volume 2. Can some one explain me about the use of air as an insulator in windows, they say it is coz of its low conductivity, how? 3. I've a got confusions about the word " net" that...

HI... i wanted to do an extensive project on electricity and i thought of something. When i take a normal conduucting wire with a plastic insulation on it, and connect it in a circuit, does the insulation affect the current carrying capacity of the wire? i mean to say in one case if i apply a...

Kapitza won his prize for low temp. physics but opted to give his http://nobelprize.org/nobel_prizes/physics/laureates/1978/kapitsa-lecture.pdf" on nuclear fusion possibilities. I was interested in the plasma thin layer heat insulation effect he mentions, as I wasn't previously familiar though...

Homework Statement Hi guys, thanks in advance! I am trying to wrap my head around some insulation problem I have been given. I think I got it but just want to be sure, this stuff still confuses me. Did do so well on the midterm! The problem about a joe's heated outdoor steam house...

I'm constructing an typical electromagnet, wrapping coil x amount of times around a 1" diameter iron bar, and getting power from 'D' cell batteries. My question is how thick can the wire's insulation & jacket be? Most of the examples I've seen used a nail, with 22-26 gauge copper or magnet...

can u explain to me why or give me a link of a website, my guess is because it absorbs the remaining heat during winter time

hey everyone I am new on the site and I've had a burning quistion in the back of my mind for ever will M.U. metal work as a magnetic insulator? if so, could you make the magnetic waves travel in a beam like light. PLEASE answer think about this, i really need everyones help. -frozendreams

hi friends, I'm an engineer, & recently I face a problem to calculate the thickness of the insulating material in the inlet gas duct of Waste heat recovery type boiler. Actually, we are executing a project, that the waste coke oven gas is used for generating steam. for this we introduce a gas...

I have an occasion to earn some money over the summer doing that building insulation or something like that, and I'm not sure whether I can handle it, meaning is it hard to do? After all, I don't know what insulation really is but from what I got by google, you just put some stuff to warm up a...

how good an insulator is asbestos? (thermal conductivity 0.15 W/ m K). I am trying to determine the thickness of insulation required to reduce the heat loss of a spherical container by half. The answer I calculated it to be is 0.2cm which to me doesn't seem right (too small?) but having no...

Hy! I made a bet with a friend. He said that at absolute zero, there is no movement so a conductor becomes an insulator (remember, it's about conductors, not semi-conductors). I say the exact opposite: because at temperatures near absolute zero a conductor becomes a super-conductor there is no...

hey there, I was asked to write a paper on the physics of beverage containers for a prof, and i was wondering if anyone had any ideas/references i could look up? I will be discussing different types of beverage holders (cans, glass and plastic bottles, styrofoam cups, mugs, beer kegs ect) and...

We have to to a report in our chemisty class on heating houses. One aspect is the window. Our teacher says that good windows are filled with argon becuase they have a high specific heat. but looking on the internet I seem to find the specific heat of argon to be about 520 J/kgC which is...

! ATENTION HERE ! Insulation of magnetic field. [?] I don't know much about what I am about to ask on this forum (isn't it what this is all about?!)... My question is about MAGNETISM(I was hoping that this is the easiest way to get the answer from someone who feels her/himself competent)...