Why does coffee go cold no matter what you do,put it in a thermous, put in 100 degree weather why cold so fast

Question

Why does coffee go cold no matter what you do,put it in a thermous, put in 100 degree weather why cold so fast

Answer 1

the law of cooling. it's an equation.

Answer 2

Hi,

as long as coffee's temperature is higher than its surrounding, the coffee will try to get to that surrounding temperature and after that it will not cool any more. The phenomenon of such type of heat transfer is called radiation. The equation for radiation is a it difficult to understand for you, and I am mentioning Convection heat transfer equation with some modifications:

Heat lost = mass of coffee x specific heat capacity of coffee x difference in temperature of coffee and surroundings x system thermal efficiency

The system thermal efficiency is normally equal to unity (1) when dealing with simple systems, but in the case of coffee, the system is not simple and there is different heat transfers. Such as in the case of coffee in the cup in an open atmosphere, the heat transfer from the surface will take place directly between the coffee and the atmosphere, but along the cup heat will first pass through the cup walls and then to atmosphere. In the case of thermous, the heat will first pass through the inner wall of the thermous, then the vaccuum, then the outer wall and then to the atmosphere. Note that this heat transfer will take place until or unless the temperature of the coffee and the surroundings become equal and the difference between these temperatures is zero.

Hope to answer you well. Keep smiling. Bye.

Answer 3

When you put a ice cube in a glass of ROOM temperature water it cools the water. Right, Ever notice that the top of your glass of water is colder then the bottom. Eventually with more cubes the heat will rise from the bottom and also be cooled. But. When you leave that glass of water out it goes warm. Actually is just adjusting to its surroundings(electrons)or adams. The hot cup of coffee is forced to be hot. Your coffee machine heats up your water. HOT forces electrons to move fast. Faster mean friction and heat. When away from the source it slows down. It blends in with your room temperature. Ever want to be like everyone else(example) thats what you coffee is trying to do. But if you where ina room and 140 degrees F  your coffee would be that hot to.

When the room temp drops the coffee will not drop as fast because liquid holds heat better then gases because liquid adams dont have as much room as gas adams have so it will take longer for them to slow down. AIR or ATMOSTPHERE(GAS) cools and heats up faster. Solids Tightly packed adams take longer to heat up but stay hot longer because of restiction on movement of adams. Liquid heats up and cools faster then solids because of freedoom of movement but holds heat longer then gases because gases have faster moving adams(thus allowing it to slow down faster). Your themostate is a solid that holds heat to keep the liquid from losing its heat. BUT the heat wll be transfered from the coffee to your thermo then to the surrouning atmosphere(your room). Thus without constant heat your coffee will ALWAYS lose is heat.