On the other hand, if the fan speed is too slow, the air in the heater core would mostly be close to the same temperature as the core-and Newton's law of cooling says that it won't pick up as much energy as it could if it were cooler.
32.
But hot things lose heat energy faster than cold things ( my simplest way of putting Newton's law of cooling ), so the house will lose more than X units of heat over the course of the night, so the furnace will have to generate more energy overall to keep the house warm.
33.
While the obvious answer revolves around the fact that the rate of heat loss is proportional to the difference in temperature ( Newton's law of cooling )-which naively appears to prove that a colder freezer would make ice faster-but it's not " necessarily " correct in this case.
34.
Fourier published his work on heat flow in " Th�orie analytique de la chaleur " ( The Analytic Theory of Heat ), in which he based his reasoning on Newton's law of cooling, namely, that the flow of heat between two adjacent molecules is proportional to the extremely small difference of their temperatures.
35.
Newton's law of cooling ( in the form of heat loss per surface area being equal to heat transfer coefficient multiplied by temperature gradient ) can then be invoked to determine the heat loss or gain from the object, fluid and / or surface temperatures, and the area of the object, depending on what information is known.
36.
Newton's law of cooling says that the rate of heat loss is proportional to the temperature difference "'multiplied by the surface area "'- so if adding the cream drops the temperature difference by less than it increases the surface area-then adding the cream early results in cooler coffee than adding it later.
37.
:: : The rate of energy loss is dependent on the square of the temperature difference between the inside of the freezer and the outside ( Newton's law of cooling )-so from a purely theoretical point of view, we don't care what's inside the freezer-only what temperature it's at.
38.
So I would still go with the white cup, entirely based on Newtons law of cooling, without having to invoke black-body radiation or crackpot ice cream manufactures ( and yes, I do know it does work despite sounding crackpot ) . "'Sp in ni ng Spark "'21 : 04, 30 March 2008 ( UTC)
39.
Because Newton's law of cooling says that energy loss is proportional to the SQUARE of the temperature difference, when we have to cool the freezer down from the upper limit of the thermostat to the lower limit, it's going to be easy to reduce the temperature to start with-and get progressively harder as the temperature drops-so we don't have a linear system here.
40.
In such cases it makes sense to talk of a single " object temperature " at any given time ( since there is no spatial temperature variation within the object ) and also the uniform temperatures within the object allow its total thermal energy excess or deficit to vary proportionally to its surface temperature, thus setting up the Newton's law of cooling requirement that the rate of temperature decrease is proportional to difference between the object and the environment.
