Answers

2016-05-12T14:04:09+05:30


Conduction is simply the flow of heat following physical contact. If you touch a hot flat iron, you will get burned (heat flows from a flat iron to your finger because they are in contact with each other). Different objects conduct heat differently; certain things conduct heat very well (like metals), and some do not (like plastic). When we touch an object to feel its temperature, what we feel is not the temperature of the object, but the temperature of our skin. To expand, when we touch a cold object, heat from our skin transfers as a result of conduction to the object, making our skin colder. Thus, we “feel” that the object is cold. This method of sensing temperature is not accurate since, as I said, different objects conduct heat differently.

Convection

Convection is heat transfer due to motion of a fluid (liquid or gas). Hotter fluids become less dense and rise up, while colder fluids become more dense and go down. When we heat water in a pot, the water at the base of the pot will become hotter first. When this happens, the hotter water at the bottom will go up, replaced by the colder water above. This, in turn, will get hotter and then go up, replaced again by the water on top. This way, heat isConvection


Convection is heat transfer due to motion of a fluid (liquid or gas). Hotter fluids become less dense and rise up, while colder fluids become more dense and go down. When we heat water in a pot, the water at the base of the pot will become hotter first. When this happens, the hotter water at the bottom will go up, replaced by the colder water above. This, in turn, will get hotter and then go up, replaced again by the water on top. This way, heat is transferred to all of the liquid in the pot evenly.
















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