why does the coffee go cold ? what causes heat loss?
552685
He could also turn up the thermostat so that the temperature of the room equals the desired temperature of the coffee.
7710
It's something that takes heat out of a physical system as opposed to a heat source which adds heat to the system. If you stir your hot coffee with cold metal spoon, the spoon takes heat out of the coffee and cools it. The spoon is acting as a heat sink.\n\nIn electronics, heat sinks are attached to components to help cool them. If the CPU of your computer as a metal object with fins sitting on top of it, that's a heat sink.
66058
Dunce girl almost has it right.  Due to the surface tension of the coffee, there's a compounding effect of greater surface area at the edge of the menicus AND a disproportionately higher concentration gradient.  Hence when the liquid evaporates, since it contains higher concentration of solids, there will be a darker edge.
654994
has it always been like this or just lately? coffee do work as diuretics- causing the loss of water in our body through urination. but they symptoms lasting for several hours sound very severe. could it be that you're intolerant towards caffeine? give decaf a go- i know what's the point of taking a decaf when you want the caffeine to keep you alert. if these persists, and you want your energy- there are other options. energy drinks, ginseng tea, and many more. hope that you're able to find a way through this. take care!
46526
it doesnt, however the energy is lost faster in hot water than in cooler water.  The rate at which all water freezes is the same.
659958
sure- it's easy- the refrigeration system moves heat out of one area into another- and simple experiment for you to do, is take a can of pressurized spray whatever, and spray it- can gets cold from reduction in pressure, allowing molecules space to "slow down" because they quit "bumping" from being in a tight spot- making room for more heat- or "making" cold- with me so far? now just picture a system with a pump that packs the gas molecules tightly together, and on the other end has a spot for them to expand (making room for more heat)and then runs the "heated" expanded gas through a radiator (heat comes out) and then gets compressed (packed) again- round and round "absorbs heat- moves heat- loses heat" \n hope this helps- if you really need more help email me through answers and I can provide pictures of how it works.
747619
Does it have to be a material? the best solution for this would be to have 2 cans one just inside the other with a compleat vacume between them, as there is no air to transmit the heat between them the liquid inside wont change tempreture.\n\nthis is the principle of a thermos flask,\n\nif you need an actual material, somthing that would trap air to stop it from moving and spreading the heat such as glass fiber like you might have in your loft\n\nhope this helps
978480
Yes, in some specific circumstances, hotter water freezes faster than colder water.  All explanations are still hypotheses and there is no fully proven explanation yet for why.  It's known as the Mpemba effect.
427543
This can happen normally if you are cold and a chill runs through you. Sometimes it's just something spontaneous even if you aren't cold. But if it's somethign that happens all the time, I don't know what it could be.
807714
It depends entirely on the temperatures of the all the components. Presumably you have liquid coffee, a coffee cup of any given material, the air temperature where you are making the coffee and the milk. So all these factors have an effect on each other as far as temperature is concerned. The second rule of thermodynamics is loosely but easily remembered by "Heat as a ruler flows from hotter to the cooler." So if your coffee is colder than your milk, the coffee gets warmer. If the air is colder than the milk, which is colder than the coffee, then the coffee will cool down super fast. If the mug is hot, it will offset the heat loss to the air and milk and so forth. The possibilities can be endless. but a basic answer is: If the coffee and mug are hotter than the milk and the air, and if the air is colder than the milk, then the coffee cools faster before adding the milk, heat flowing from coffee to the air. Adding milk warmer than the air slows the transfer down, as it has added temperature warmer than the air to the equation. If the milk is colder than the air then the heat exchange is speeded up.
1083390
The water around an iceberg or floe becomes colder than freezing (like putting ice cubes in a drink), but won't turn to ice since it is salty.  And waters in the polar regions are down near freezing to begin with.  When the berg gets sunlight some of the surface will melt off.  When the berg finally drifts to warmer waters, it will melt until it is gone.\n\nFor an example: Take a sink and fill it with water.  Put in some rock salts and stir until dissolved.  Now put in several trays' worth of ice cubes.  Stir.  Some of the cubes will melt since the tap water was not freezing, but eventually the sink water will get to a temperature below 32 degrees F or 0 degrees C without freezing solid.  At that point the coldness of the water keeps the remaining ice cubes frozen and the ice cubes keep the water at a below freezing temp.  Eventually it will melt cause there will be heat absorption into the system raising the water temperature, but it will take awhile.
1102012
the change back to room temp. with the alcohol  in the mix is what causes it. I used to own a bar and I would keep the coolers at about 28 degrees  the beer wouldnt be froze till you took it out and opened it  then it would freeze right in front of the customer,,,,,, they just loved it  ,,,,, they knew they were getting the coldest beer in town.!!!!!!\n\nS
979541
This is a pretty straightforward problem which you would have gotten a faster answer to if you put it in the chemistry section, eh?\n\nOK, the coffee is going to cool down from the ice. How much will it cool down?\n\nFirst you have to warm up the ice to 0 degrees so that it can start to melt. So figure how many calories it takes to warm 23 g of ice by 2.2 degrees.\n\nOK, now you have to melt 23 g of ice. So figure out how many calories it takes to do that. \n\nThose calories have to be removed from the temperature of the coffee. So you have to reduce the temp of the coffee enough to give you those calories. One degree drop of temp of the coffee gives you a callorie for each mL of coffee, right?\n\nOK, so now you have 23 g of water at 0 degrees, and 248 mL of coffee at a little less than 98 degrees. It's a little equation -  the temp of the 23 g plus the temp of the 248 mL will give the temp of the total of 271 g (or ML) \n\nPiece of cake.
99485
no. because something could be steaming when it is cold.
145994
The metal spoon is a good conductor of heat. It also has a handle that protrudes out, with a fair amount of surface area to radiate heat out, and the spoon will also cool by convection. This definitely will cool the coffee down faster.
81857
When the coffee is first poured in the molecules in the ceramic are further apart, because cold things shrink (just ask George Costanza) thus causing more room between molucules and creating a lower pitch, but as the coffee heats the mug the molecules expand, reducing the distance between each molecule and raising the pitch.
811304
let thetemperature of the mix be 't'*Cfind the heat lost by coffee\nfind the heat gained by ice in three stages\na)from -2.2*C to 0*C\nb)for melting and becoming water at 0*C\nc)for getting to the equilibrium temperature of the mixture\nequate and solve