How can a thermos keep hot things hot and cold things cold?

Answer 1

high tech

Answer 2

It has a double wall layer that creates a good insulator. Heat tries to transfer out from an object to the colder space and does this slowly with the insulator in the sleeve of the thermos. The temperature tries to be even both inside and out. The outside is 'room temperature'.If it was freezing out side of the thermos the heat transfer would be slowed greatly. The same is true for the reverse.Cold also tries to meet the temperature out side of the container! if you had a cold drink it would try to freeze if the out side was below freezing but the process of transfering would be very slow.

Answer 3

It has two layers separated by a (partial) vacuum. Thermal energy can only be conducted through matter, so a vacuum is a very poor conductor (i.e. it is a very good insulator). Also with the lid on it prevents heat transfer by convection and radiation as well.

If you filled an uninsulated container, perhaps a steel bowl, with something hot (say 200 degrees fahrenheit) in a room where the air temperature is 70 degrees it immediately begins to transfer its heat into the room primarily by conduction and convection.

If the contents is at 20 degrees the heat from the room transfers to the contents in the same way.

In either case a sealed, insulated container slows (but doesn't stop) that heat transfer.

Answer 4

The thermos is a pitcher or metallic field that seals interior the liquid. It purely insulates the liquid from the outdoors for a whilst. Even the terrific thermos flasks purely artwork for hence long. A warm thermos of coffee will final from 6 AM by supper at approximately 5. After that, it will be rather cool. same with a chilly thermos of milk. After sitting some hours, this is going to anticipate room temperature.

Answer 5

There is a layer of foam or other poor temperature conducting materials between the liquid inside and the air outside, like an oven mitt allows you to touch a hot pan without getting burned. If the oven mitt were made of a good temperature conductive material like metal, it would quickly heat up (or cool down) and you would feel the temperature on your hands. Try this: Get a hot cup of water (don't burn yourself) and get a metal spoon and a wooden popsicle stick. Put them both in the hot water for a minute then feel the dry ends of them. The metal will feel warm like the water (because it is a good conductor) and the stick won't be very warm (because it is a poor conductor) You can repeat this with similar findings with a cup of cold water as well.

Answer 6

the thermos bottle keeps the outside atmosphere from affecting the temperature of the contents inside. If the contents are very hot or very cold, the atmosphere outside is either much cooler or hotter than the contents. The thermos just insulates the contents from the outside "air", that is all.

Answer 7

It's really quite simple. Because of the insulation in the thermos, whether it be a cold liquid or a hot one, it traps in the temperature for a period of time.

Answer 8

Between the plastic outside part and the glass or aluminum sheet inside there's a mass of foam (insulation), which is composed of millions of bubbles that keeps the cold or the hot inside the glass or the aluminum container acting like a barrier.

Answer 9

people will say insulation. However, as a scientologist, i submit that it is the forbidden power of xenu, the intergalactic soul keeper. HIm and his armada of dc-8s will destroy us all. Also, what the thermos is made of can become neither cold or hot, if it could become either, the liquid inside would be warmed or cooled by the outside.

Answer 10

Insulation. It keeps the hot in, and the cold out. Then if you have something cold it does the opposite. Its made like that. It just does it. Be thankful you have it.

Answer 11

They have sensors that can tell the temperature of the product being placed inside. If it's hot, the sensor's tell an internal combustion engine to radiate a certain amount of heat to keep the product at the same temperature. If it's cold, the sensor tells an internal, nuclear powered refrigeration unit to keep the temperature cold.