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Q: Why can a vacuum flask be used to keep cold liquids cold?
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What is the name of the thing used to keep liquids warm or cold?

Vacuum flask.


How does vacuum flasks keep hot liquids hot and cold liquids cold?

by inhibiting heat conduction


What Vacuum flask keeps liquid at same temperature?

There is no way to permanently store heat. The most you can expect, from a high-quality vacuum flask, is to keep the liquid cold, or hot, for a fairly long time. But gradually, some heat will seep in, or out, until the temperature in the vacuum flask will be equal to the temperature of the surroundings.


Vacuum is mantained in thermos flask?

The vacuum reduce heat loss by conduction and convection.


How does a vacuum flask keep tea hot?

Insulation


What can be held in a thermos flask?

Hot drinks such as tea and coffee are usually held in a thermos flask. The flask will keep the drink warm for several hours when one is outside or on the move. Cold drinks can also be kept in them or even non drinking liquids that one wishes to keep at a steady temperature.


What container will keep liquids hotter for longer periods of time?

A Flask


What is the Functions of thermos flask with diagram?

The primary function of a thermos flask is to keep liquids hot or cold. There is an outer protective layer with a hollow area inside before the actual area where the liquid is stored. Heat or cold gets trapped in the hollow area and that is what keeps a liquid hot or cold.


Why vacuum flask keep cold liquids cool better than hot liquids warm?

It is due to heat transfer by radiation. You must first understand all objects emit some radiation, even room temperature items, but hotter items release greater radiation. With a hot liquid, the vacuum flask is releasing heat via radiation (radiant heat) outwards into the surroundings, the surroundings mostly absorb this radiant heat, therefore the radiant heat is constantly lost to the surroundings. However, with a cold liquid the radiant heat is transferred from the surroundings to the vacuum flask, where the vacuum flask is a relatively small "target" for the radiant heat to strike. Therefore the cold liquid only receives a small amount of radiant heat from the surroundings and thus changes temperature more slowly. Think of it this way: The surroundings is a very very large "target" for the heat released from the thermos to strike, while the thermos is a relatively tiny target for the heat from the surroundings to strike, thus it is easier for the thermos to lose heat than it is to absorb heat from the surroundings.


Why does tea stay hot in a glass teapot?

Heat can be transferred in three ways: conduction, convection, radiation. In a vacuum flask, conduction and convection are greatly reduced through a vacuum (hence the name!) between two glass layers, whereas radiation is greatly reduced by the mirror coating on the same glass. As a result, heat takes much longer to get out - or in, since you can also keep cold things in a vacuum flask.Note that no vacuum flask will keep things hot (or cold) indefinitely; it simply takes much longer for hot things to cool down, or for cold things to heat up.


What is a Flat bottomed Flask and how is it used?

It's a flask with a flat bottom. It's used for containing liquids when you don't want to have to use a stand to keep it from tipping over.


What is used to keep liquids warm and cold?

a insalator keeps liquids warm