Why is black colour good absorber and radiator of heat ?

In summary, black is the color of objects that do not emit or reflect light in any part of the visible spectrum; they absorb all such frequencies of light. This is why black color is good absorber and radiator of heat.
  • #1
sankalpmittal
785
15
I have read in my class 10th book and other books that black(usually dark) colour is avoided in summers and this is the reason why impure ice melts quickly .

I am wondering why ?
 
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  • #2
By definition of the word "black".
 
  • #3
The color of any object is the light it reflects. An object is white if it reflects all or almost all of the light falling on it (and so absorbs little light). An object is black if it reflects no or very little light (and so absorbs almost all light). And, of course, light is energy. Absorbing little light only a slight increase in energy, absorbing a lot of light means a larger increase in energy and so a larger increase in heat.
 
  • #4
russ_watters said:
By definition of the word "black".

Why is black colour good absorber and radiator of heat ? (usually dark colours)

How ? By definition ??
 
  • #5
HallsofIvy said:
The color of any object is the light it reflects. An object is white if it reflects all or almost all of the light falling on it (and so absorbs little light). An object is black if it reflects no or very little light (and so absorbs almost all light). And, of course, light is energy. Absorbing little light only a slight increase in energy, absorbing a lot of light means a larger increase in energy and so a larger increase in heat.

Yes you are absolutely correct but why black colour absorbs large amount of light as compared to white .
 
  • #6
russ_watters said:
By definition of the word "black".

HallsofIvy said:
The color of any object is the light it reflects. An object is white if it reflects all or almost all of the light falling on it (and so absorbs little light). An object is black if it reflects no or very little light (and so absorbs almost all light). And, of course, light is energy. Absorbing little light only a slight increase in energy, absorbing a lot of light means a larger increase in energy and so a larger increase in heat.

Got you ! Thanks russ_watters . The answer to this question was by definition of word black .

Black is the color of objects that do not emit or reflect light in any part of the visible spectrum; they absorb all such frequencies of light. Although black is sometimes described as an "achromatic", or hueless, color, in practice it can be considered a color, as in expressions like "black cat" or "black paint".
http://en.wikipedia.org/wiki/Black


So black absorbs all the frequencies of light and doesn't reflect so more heat is produced in that , right .


Thanks to you all who replied .:smile:
 
  • #7
sankalpmittal said:
So black absorbs all the frequencies of light and doesn't reflect so more heat is produced in that , right .
Yes.
 
  • #8
Redbelly98 said:
Yes.

OK Thanks .
 

1. Why is black color a good absorber of heat?

Black color is a good absorber of heat because it is able to absorb almost all wavelengths of light, including those in the infrared spectrum. The molecules in black objects are able to absorb and retain the heat energy from these wavelengths, making it a good absorber of heat.

2. How does the color black affect heat absorption?

The color black affects heat absorption because it has a high level of absorbency for visible and non-visible light. This means that when light, and therefore heat, hits a black object, it is absorbed rather than reflected. The absorbed heat energy then causes the molecules in the object to vibrate and increase in temperature.

3. Why is black color a good radiator of heat?

Black color is a good radiator of heat because of its high emissivity. This means that black objects are able to emit heat energy at a faster rate compared to objects with lower emissivity. The molecules in black objects are able to release the absorbed heat energy quickly, making it a good radiator of heat.

4. How does the color black affect heat radiation?

The color black affects heat radiation because of its ability to absorb and emit heat energy. When heat is absorbed by a black object, the molecules vibrate and release the heat energy in the form of infrared radiation. This process allows the black object to cool down faster compared to objects with lower emissivity.

5. Is black color always the best absorber and radiator of heat?

No, black color is not always the best absorber and radiator of heat. While black objects do have a high level of absorbency and emissivity, there are other factors that can affect the absorption and radiation of heat. These include the material and surface properties of the object, as well as the temperature and wavelength of the heat source.

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