Planck's Formula - Help undressing the question needed

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In summary, the conversation discusses using Planck's formula to plot the wavelength dependence of the intensity of black body radiation in order to estimate the temperature at which an object glows red hot. The question author suggests using the peak of the distribution in the red part of the spectrum for this estimation, while the other person suggests setting the peak at the infrared edge of visible or at the high-f inflection point. They also mention the importance of including the infrared part of the spectrum in the plot, despite it not being visible to the human eye.
  • #1
Brewer
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I have a question that asks me to plot Plancks forumla for the wavelength dpendence of the intensity of black body radiation, and to use it to obtain an estimate for the temperature at which an object glows red hot.

Now I know Planck's formula (or its written in front of me), but I don't know what band of wavelengths I should plot. The EM spectrum? Other random wavelengths?

And for the red hot bit, is that the point at which the peak of the plot goes over a certain wavelength? The infra red end of the spectra?

Any help would be appreciated.
 
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  • #2
Plot the portions of the spectrum that contain noticeable intensity ...
for a Temperature at which there's noticeable intensity in the "red".

The question author probably expects you to use a Temperature at which
the PEAK of the distribution is red (for whatever variable your equation is in)
- but this would appear orange-hot, with significant orange and yellow -
I would rather set the peak at the infrared edge of visible ...
even better, set the high-f inflection point at the infrared edge of visible.

[just because HUMANS can't see it , doesn't mean it isn't worth graphing!]
 
  • #3
So it is the point at which the peak of the graph is in the infrared part of the spectrum then?
 

1. What is Planck's Formula?

Planck's Formula, also known as Planck's Law, is a mathematical equation that describes the energy distribution in blackbody radiation. It was developed by German physicist Max Planck in 1900.

2. How does Planck's Formula relate to the electromagnetic spectrum?

Planck's Formula is used to describe the distribution of energy in different wavelengths of the electromagnetic spectrum. It helps us understand how much energy is emitted at different wavelengths by a blackbody object.

3. Can you explain the mathematical components of Planck's Formula?

Planck's Formula is expressed as E = hc/λ, where E is energy, h is Planck's constant, c is the speed of light, and λ is the wavelength of the radiation. This equation shows that the energy of a photon is inversely proportional to its wavelength.

4. How is Planck's Formula used in modern science?

Planck's Formula is used in many areas of modern science, including astrophysics, cosmology, and quantum mechanics. It helps us understand the behavior of electromagnetic radiation in various systems, and it has also been used to develop technologies such as solar cells and infrared cameras.

5. What are the limitations of Planck's Formula?

Planck's Formula has some limitations, as it is based on the assumption that blackbody radiation is continuous and does not take into account the quantum nature of light. It also does not account for relativistic effects. However, it is still a useful tool for understanding and predicting the behavior of electromagnetic radiation in many situations.

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