What is Cooling: Definition and 638 Discussions

I've got a question to solve.. Just need 1 thing.. An automobile cooling system holds 18L of water. How much heat does it absorb if its temperature rises from 20ºC to 90ºC? I need to find how many kg of water I have... and then plug into Q =mc(T1-T2) Q = (m)(4186)(-70) Look...

A cooling system that pumps 177,21 kg/s of water in a tunnel warmed by trains with an average thermal output of 37,125 mega watts. I have to estimate the energy which is necessary to run the system in order to cool down water with the mass M. Both in the general case and on the assumption that...

Hi Guys! well! I am studying vapor powered cycles nowadays. The topic which I am studying currently is The Rankine Cycle. I came across a question in my book . which i want you to help me out. It is said that in the rankine cycle, in the condenser, 2000 kg/s of cooling water is used to...

in a book says cooling by demagnetization can be explained in terms of reduced entropy. As far as I know, entropy is associated with order. More order we have (i.e. more spin alignment), then less entropy S. Demagnetization results in disorder, since spins are more disorder, thus higher...

I have a cooling system where the condenser has an effect of 131 kW. The text says that the condensor-heat can be recirculated using the ventilaton-system 5 months a year, and that the vent.system is running between 0800-2000 monday to friday. I also have the energi price pr kWh. The...

I wanted to use air conditionar for cooling my machine. For that purpose i design one air blower and installed it in an air conditioned room. my machine is about 20 feet far from the room. so i have arranged one 6" pvc pipe for air traveling. I wanted to put the pipe inside my...

I know what this law says, but I don´t know where does it comes from. Could somone please help me with the derivation of this law? Thanks in advance.

I did a problem where I was asked to model a simple cooling graph. No big deal. I got my model and found my constant values by using initial values. Now comes the sticky part. I am asked to create a model similar to the previous simple cooling problem for a more complex system. Keep in...

Saw a lovely view today and couldn't resist parking up to snap it. It's a pair of abandoned cooling towers. The power station was demolished years ago, but they can't blow up the towers because the M1 runs right next to them, as you can see...

hi. i am not chemist, and i am looking for some simple reactions which can happen at room temperature and it creates cooling after reaction, i.e. it absorbs energy. any body know some examples? :confused: thanks.

As was discussed in another thread, About the rough idea of the greenhouse effect and the temperature of the troposphere I said: So we test the hypothesis and see no troposphere warming in the measured radiosonde data and a distinct lower warming trend in the calculated satellite data...

Can anyone give me a formula for calculating the energy needed in cooling a room? The room has to be at 10c maximum, regardless of outside temperature. as there are several rooms all with differing volumes, can a formula for 1000 cubic meters be used. Thanks.

Our air conditioner has broken so i was bored and started thinken about something. I calculated that a 10 pound bag of ice will cool my room (which i figured is about 4500 ft^3... yah... i love my room lol) from about 86 freaken degrees! to about 72 degrees fahrenheit. In my calculations i...

Can someone point me to a website or book that explains why nuclear cooling stacks are shaped the way they are? (i.e. hyperboloid) -Burg

1989 GMC truck 4 cyl 2.5 liter The overheat light comes on after about a minute's driving. I have flushed the system, replaced the hoses, replaced the whole radiator, and the coolant temperature sensor and the thermostat(tried two separate new thermostats). I tried removing the thermostat...

this was in a quiz i did ages ago and i never found out the answer. someone makes 2 cups of coffee. Cup 1 has coffee then water then milk added and is left to stand for 15mins. Cup 2 has coffee then water added then is left to stand for 15 mins, then milk is added. which one would be hottest...

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...

A cup of coffee at 174 degrees is poured into a mug and left in a room at 76 degrees. After 5 minutes, the coffee is 134 degrees. Assume that the differential equation describing Newton's Law of Cooling is (in this case) dT/dt = k(T-76) here's what i done: y(0) = 98e^{kt} y(5) = 134-76...

how does the cooling capacity of an aircon compressor exceed that of the power supplied to it? from what i understand, energy cannot be created or destroyed. so when we put in 500W of electrical energy into a compressor, why do we expect the cooling capacity to be 1500W. does that mean that...

I just read computers are going to run cooler because of capacitor cooling. What type of circuit is involved and how could I cool a small cap on the bench.

I am stumped on one question out of twenty on my lab report. T = T0e-kt + Troom When T = 0 what is the value of e to the negative kt

Can someone help me explain how a plate of metal's yield strength changes as it is 1) Rolled (flattened) then 2) Heated for some hours and cooled, and then finally 3) Cooled and rolled additionally. Does the yield strength increase at first, then drop, and then increase again? That's what I...

ever saw this one? :rofl:

Air conditioner cools the air in a room with a power of 8.4*10^6J/h. Volume of the room is 62.5m^3. At first the air is at the temperature of 30C and air pressure is 1atm, which stays a constant. How long does it take to cool the room to 25C? Note that the air shrinks while cooling down and...

Hello I've been thinking about this for a while and having consulted quite a few resources on the internet, decided to post some issues related to heat transfer by forced convection/radiation here... Stefan's Law states that the rate of heat transfer by radiation from the body to the...

Im having a bit of trouble using Newton's Law of cooling. I have been given the formula T(t)=T_s + (T_0 - T_s) e^{-kt} . I am trying to find the time of death of a body, and I am given the time the body was found 12.00pm, its temp around 90, 2nd check, at around 1.00pm, temp is 80, and the...

can someone explain algorithmic cooling to me? (i think that's what it's called.) in a work of fiction i am presently reading, an interior space is cooled by a quantum-computational device engaged in ongoing calculations. the book is 'redemption ark' by alastair reynolds and the technology is...

As part of my research, i have to find 3 pratical examples that Newtons Law of cooling can be used for. So far i have two, finding the time someone died, and cooling down soup. I have to find a third, which does not involve food, or someone dying. if anyone could suggest a good third practical...

In Newton's Law of Cooling, we have the constant k, i was just wondering (most people will prolly laugh at me) what the constant k represents, and what units this constant would have. Also, can the law describe a cold object being heated up in a warmer environment. Any help would be...

Problem 2. Liquid nitrogen, which has a boiling point of 77 K, is commonly used to cool substances to low temperatures. How much energy must be removed from 1.4 kg of gaseous nitrogen at 77 K for it to completely liquefy? Assume the latent heat of liquid nitrogen is 2.01 *10^5 J/kg Answer...

I was told that when you release spray from an aerosol can, the can cools down. Is this true, and if so, why? Does the gas in the can require outside energy to expand and escape the can? Thanks, Alex

There was this problem regarding Latent Heat that I would like further clarification: Problem: 200g of ice at -10C is added to 1kg of water at 15C in an insulated container. Is there enough ice to cool the water to 0C? If so, how much ice and water are present once equilibrium is reached...

I am considering getting into forging metal things at home as a hobby. Setting up a little smithy in the back. I thought I'd try making some blades and such. What are the properties of iron/steel as it cools? At what rate should it be cooled for different hardness or durability? What...

Hi everyone. I am doing a physic’s project about Newton’s law of cooling. This project was basically to evaluate the change in temperature between a cup of cooling water and the room temperature as a function of time by using different methods of heat retention (via convection & evaporation...

I am having a problem at work and I'm hoping some of the brains on this board can help. I'm using a Focused Ion beam to induce insulator deposition using a siloxane liquid. The liquid is stored in a small container with a valve to let the gas escape the container. This small container is...

I figure that you guys must know fluid dynamics better than most physicists so here's my question: Open your mouth wide and exhale and it's hot air you feel. Now pucker your lips and exhale and it feels cold (unless you hold your hand right up close to your lips). Is this an example of the...

Summer project: Watercooling a computer so it is a quiet as possible. I have a computer case where the ambient air temperature is around 37’C and the room temperature is around 20’C. I will be cooling two processors rated at 54.6W by piping water over them serially to a radiator which can...

[SOLVED] Cooling Towers I was just wondering how cooling towers in nuclear reactors work. I've read many different versions of a cooling tower's task, but they all seem to be different from one another. I'm writing a webpage on nuclear energy and was just wondering. Thank you all very much