Heating Definition and 616 Threads

I don't know whether this is appropriate for this sort of forum, but what would be the difference between microwaving standard tap water and boiling it in a kettle? Not just any water, but hard London tapwater (eek), with all sorts of delicious impurities. There's a marked difference in...

How do we Calculate Temperature & Time of Heating Element Heating Wire having the following Data : SWG 16(1.63mm) Specific Resistivity = 1.45 ohms-mm-3 Density = 7.1 gm-cm-3 Resistance = 0.685 ohms/Meter Weight = 15 Gram/Meter (a)In order to Build Heating Element using the above wire for...

Heating Wire having the following Data : SWG 16(1.63mm) Specific Resistivity = 1.45 ohms-mm-3 Density = 7.1 gm-cm-3 Resistance = 0.685 ohms/Meter Weight = 15 Gram/Meter (a)Please help me in this Project to Build Heating Element using the above wire for Making 2.5 KiloWatt heating Element...

HI, If you compressed 300 litres (about 12 moles) into a 3 litre cylinder which was already at 3,000 degrees C. Would the air reach this temperature in an instant? Im trying to get my head around this stuff about heat capacities and amounts of energy needed to heat materials. Please...

I was wondering if a heating device is installed in a building, and the building is good enough(no open windows). And would there be heat loss during the night time when all the doors are closed?

A generating station is producing 1.4e6 W of power that is to be sent to a small town located 7.0 km away. Each of the two wires that comprise the transmission line has a resistance per kilometer of length of 5.0e-2 \Omega/km. (a) Find the power lost in heating the wires if the power is...

I need help to understand heating requirement in an incinerator meant for aqueous wastewater; The wastewater is evaporated in a primary chamber and then the gases are required to be heated to 1200 deg.C in a secondary chamber with 2 seconds residence time. The operating pressure is just...

I have a copper coin with a hole in the centre. The hole is a circle. If the coin is heated, the metal will expand towards all directions in and out, so the radius of the circle will be decreased. Correct?

From http://little-giant.com/pool_heating.html" (The section entitled "Little Giant® Sizing For Swimming Pools General Requirements" about halfway down the page) "Using these standards, the thermal conductivity is 7 BTU/Hr. Sq. Ft./°F or 140 BTU/Hr. Sq. Ft. 20°F difference. " Is this...

A central heating system has been thought to run with temperatures 80/60, and so the flow of water through the system has been calculated accordingly. Now it turnes out that it will run with 60/40 instead. In order to have the system deliver the same effect, I assume more water will need to flow...

hello all! If there is a circuit with only one heating element, how do we calculate the power it requires? According to the physics formula P=V^2/R, whenever you increase the resistance, the power it requires falls. However, I don't think that's right. Or is it? When R is increased, so...

What physically happens to the water when you heat CaCl2*2H2O above it's decomposition temperature 175 deg C? Does the water just vaporize? Or does it partially dissolve some of the calcium chloride in an aqueous solution and then boil away?

I have the following scenario and hope one of you can help me. I need to find an equation describing a heating process. A cylindrical metal of known dimensions and properties is heated from one side while the temperature of the other side is kept constant. I need to find the equation describing...

Homework Statement A barrel of diameter D at 20 degrees Celsius is to be enclosed by an iron band. The circular band has an inside diameter of d at 20 degrees Celsius. It is w wide and t thick. (a) To what temperature must the band be heated so that it will fit over the barrel? (b) What will...

Homework Statement A flask with a volume of 2.70 L, provided with a stopcock, contains ethane gas (C_2 H_6) at a temperature of 297 K and atmospheric pressure 1.01×10^5 Pa. The molar mass of ethane is 30.1 g/mol. The system is warmed to a temperature of 396 K, with the stopcock open to the...

HELP!:Real-World Heat Transfer, heating water ... Can someone help me with this problem? :confused: Suppose you have a carton of milk out of the fridge. It is most energy efficient to: a.) immediately return it to the fridge b.) leave it out as long as possible I am not sure whether...

I'm very excited. I just finished ordering all the necessary parts to install a solar water heating system. With the likelihood of electricity only getting more expensive, coupled with the likelihood of my 3 children getting bigger, It seemed like a no-brainer. Who else has solar heat...

Hi, I would like some help/orientation about heating furnaces. The issue is around the heating of steel billets (continuous cast billets). The furnace needs to heat a load of 104 billets placed face to face along its longitudinal axis from ambient temperature to ± 1,150°C. Each billet has...

I'm making a coiled heating element from nichrome wire, and I was wondering how the coiling will affect the current. I have values for current needed for straight nichrome wire, but I believe coiling it will change the resistance. Thanks.

Is there anyone out there that can help me answer a question I have related to solar heating of water. - There is a 1" diameter x 4' long glass tube filled with water having an input temperature of 250F. - There is a 2" diameter tube surrounding it, 4' long, filled with water coming from...

Homework Statement In a circuit a 20-ohm resistor sits inside 104 g of pure water that is surrounded by insulating Styrofoam, there are additional resistors in the circuit. If the water is initially at temperature 10.5 degrees celcius, how long will it take for its temperature to rise to...

Solar Heating Project: formula Q/t= A changing T/ R Homework Statement At this moment I have a project whose due date forever looms closer and I'm still troublesome about how to conquer it. Objective: to design a solar heating system for my house building that will provide 50% of the heat...

How does an infrared photon leading to heating?

newbie here, I've been searching many forums and cannot find the questions/answers I am looking for (close, but not quite). so, I am going to ask my question in a very specific, detailed manner. i want to use nichrome wire to make 8 heating elements. they will each be a single strand...

What would you guys say is an acceptable speed of water through a general heating system with radiators and such? I'm thinking between 0.4-0.8 m/s as optimal. I'm worried that sound might become a problem with higher speeds? And also pressure loss...

Toasting in a toaster is usually considered cooking by (infra red) radiation. But the hot coils touch the toast so an element of heating by conduction occurs as well. Are they both equally as valid or is one more valid than the other. If the latter than which one and by how much? On the other...

A physicist, upon awaking one morning to find his stove out of order, decides to boil the water for his wife's coffee by shaking it in a thermos flask. Suppose that he uses 380 cm3 of tap water at 58°F, that the water falls 1.15 ft each shake, and that the physicist completes 32 shakes each...

Hi. I'm just curious why did the colour of the heating element of my soldering iron change (see the picture attached). I mean I know it's because of the heating but what exactly makes the colour change? Is it oxide? Or is it because of a change in the crystalline structure of the metal?

Homework Statement its a long story problem so ill break it down: an electric heater generates 250 Watts of electricity, how long will it take for 250 grams of water to heat from 20 C to 80 C The Attempt at a Solution so 80 C - 20 C = 60 C , i have to heat it 60 C 250 grams of water...

Suppose you have a weight hanging from a rubber band and you heat up the rubber band, will the weight go up or down? from grade-school the answer "down" was pounded into my head - obviously - when something is heated it expands! but yesterday i was reading the Feynman lectures and in the...

I have a question regarding plasma .Suppose i heat a certain amount of dioxygen , O2 , which will first easely break into oxygen and after come to a point where at least 1 electrons gets free of the oxygen atom and hence the substence become plasma according to the definition. Now , if i keep...

Hello everyone, new member here:smile:. My sister asked me this today - real-life physics at work! She's making Christmas pud & the instructions say it takes 8 hours to cook. However, her bowls are too small, so she's made two little ones instead, and she asked how long to allow to cook...

Does it sound at all reasonable that a heat-exchanger of 250 kW can heat water from 5 to 55 degrees C for about 120 "normal" appartments directly without any accumulation when probability is taken into account? If not, how many liters should be accumulated?

To what extent is Earth's surface heated by heat from the interior? There were differing opinions in my Astrobiology class today. I would guess that solar radiation is by far the dominant source, perhaps 100:1 vs interior heat. Does anyone else have a better guess, or perhaps a source or...

An electric heating coil is immersed in 4.2 kg of water at 22°C. The coil, which has a resistance of 260 Ω, warms the water to 33°C in 3.5 mins. What is the potential difference at which the coil operates? I was looking through the chapter, and did not see any equations that I can use that...

After heating some glass bottles to a very high temperature with a bonfire the bottles changed shape as you would expect molten glass to do, but once the bottles returned to ambient temperature they were extremely brittle. What is happening to cause this? I read that annealing requires heating...

INTRODUCTION:Here is a problem on "Heating Effect Of Current".I can't understand a part of it. EXACT PROBLEM: "A battery of emf E and internal resistance r is supplying current to an external resistance R.(a)Show that the power dissipated in R will be maximum when R=r.(b)What is the maximum...

Is there a way to measure the temperature in an induction oven for melting of aluminium(700 C). The pyrometer I’m using can’t correctly display the temperature when the system is running because it interferes with the induction field. The non-contact IR-camera has been abandoned because of the...

Sir, Please help me with this problem. A Volume – Temperature diagram was obtained when a gas was heated at a constant pressure. During the heating process from state 1 to state 2 how does its mass vary? Sometimes the diagram may not clear, so I will try to describe how it looks like. It...

I just bought a Wagner wallpaper steamer and I am using it to heat up water in a 55gal barrel for manure pasturization. Testing it out on a small scale, i was able to heat up 15L of water to 150 degrees in 15 minutes (perfect temperature for pasturzation at 3 hours).. The barrel will only...

2-48) The 60-W fan of a central heating system is to circulate air through the ducts. The analysis of the flow shows that the fan needs to raise the pressure of air by 50Pa to maintain flow. The fan is located in a horizontal flow section where the diameter is 30cm at both inlet and outlet...

We have an electronics enclosure that has a top with 23.3 square feet. It is painted white and I have read that a glossy white paint will absorb only 14 percent of the solar heat. That tells me that of the the 97 watts per square foot from solar radiation this top will will absorb 13.58 watts...

Amid months of criticism over failed U.S. oil policy, and after suffering embarrasing setbacks in the Senate (Democrats use of rule to demand continued pre-war intelligence committee review) and in the House (Democrat Cong. Murtha's Iraq war exit proposal), the White House and big U.S. oil were...

Suppose a constant volume of water is being heated up by a constant amount of power. After some time it is noted that the rate of change of temperature is slowing down. (In this scenario, assume all temperatures to be between 10 and 90 degrees Celcius) What would cause this non-linear...

A relatively simple question: Suppose we have a dark non-reflective body at rest in space and hit it with fair amounts of radiation. This would cause the body to heat up because it absorbs most of the radiation. After some time would the body cool down? The first guess is that it would, but why...

Spent reactor fuel continues to produce heat for a very long time and I am curious as to why this heat cannot be used for something, such as district heating. Obviously there are some barriers out there or it would be done. I'm wondering what these barriers are. Any discussion surrounding...

Is there a way to determine the "heating power" of a substance with a known specific heat and mass, onto another object of another known specific heat and mass. Say if I had a tank of water and dropped in a piece of metal for example, let the metal heat up, but not let the system come to...

http://www.venezuelanalysis.com/news.php?newsno=1736

Can someone explain to me how the photon energy can heat up a material. Shouldn't the photon energy cause interactions(photoelectric, compton etc.) How can this energy be "absorbed" to make atoms move faster?

Read this article.. http://www.exn.ca/dailyplanet/story.asp?id=2005041952