Give two examples in which transfer of heat occurs by radiation. Give an activity to show that black objects absorb more heat than white objects. Who will give the first and correct answer I will him/ her as brainlist please answer it's very urgent and important. Please give answer according to 7 class.
Answers
Answer:
A good example would be heating a tin can of water using a Bunsen burner. Initially the flame produces radiation which heats the tin can. The tin can then transfers heat to the water through conduction. The hot water then rises to the top, in the convection process.
Explanation:
In the convection method, molecules travel from the hotter region to the colder region. The case is the same when water is heated.In the process of convection, molecules move from a hotter place to a colder region. Therefore, convection is impossible in solids because the molecules are rigid and vibrate when heated. In liquids and gases, molecules are comparatively less rigid and can Radiant heat falling on a body is partly absorbed and partly reflected. Some of it may also get transmitted.Some part of the radiation are absorbed by the object, while some will strike its surface and reflect like a ball bouncing back on striking a wall. The remaining part of the radiation will pass through the object like a light passing through a glass, i.e., transmitted.n move easily, thereby making convection possible in them.The everyday uses of the principle that black objects absorb more heat than white or polished ones are as follows:
1) Cooking utensils have black-polished/black-painted outer surface to absorb more heat. This helps in cooking the food in less time.
2) During winters, we wear black or dark colored clothes, as these can absorb more heat and keep us warm than the white or dull colored ones.
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