Why does tea in an ordinary aluminium kettle cool down fast?

Answer 1

It's all about the size of an object, heat is a form of energy and the larger an object the more energy it can store, a teapot is considerably larger then a teacup, so the teapot holds more heat energy and therefore cools down slower then the teacup which holds less energy as it is smaller

Or it could be because the boiling water in a teapot is completely surrounded by material so it has no where to lose it's heat except through the spout, a teacup has no lid so the heat can escape into the air around it

Answer 2

Coffee is made and then sits on a burner on the coffee pot that is about 165 degrees. Tea is made with boiling water at 212 degrees and poured into a cup. Tea takes longer to cool because it starts out hotter.

Answer 3

The cup is smaller than the teapot so the teapot has less surface area compared to its volume than the teacup.

As a simplified example - imagine the cup and the teapot are the same shape but different sizes - let's say spheres; the teapot being an 8 inch diameter sphere and the cup a 4 inch diameter sphere. That means the cup has a surface are of 4/3·π·(2 in)² = π·16/3 in² and a volume of 8π cubic inches, The pot would have a surface area of 4/3·π·(4 in)² = π·64/3 in² and a volume of 64π cubic inches.

The surface area of the pot is 4 times that of the cup, but it has 8 times the volume - and consequently the contents have 8 times the mass. Since the heat transfer is proportional to the surface area, even though the pot has more surface area it has proportionally more contents to remove the heat from so even at 4 times the rate of heat loss, it will still only drop in temperature half as fast as the cup (4/8 = 1/2). The math is hardly exact, but the point is that volume increases faster than surface area as objects increase in size.

On top of that, the contents of the teapot are pretty much contained within it while the contents of the teacup are free to evaporate into the surrounding air - further accelerating the heat loss from the cup.

Answer 4

it is because heat enters fast and gets out fast

Answer 5

Since the hot tea is already hot, it will get hotter faster. The cold tea will take longer to brew because it has less heat.

Answer 6

It is smaller, and has less mass.More specifically, the surface-to-volume (and therefore surface-to-mass) ratio is generally larger in the case of smaller objects.

Answer 7

Cup OF Tea