- #1
Fluxthroughme
- 71
- 0
Part a) is correct, but the book gives me an answer of [itex]2.3*10^{23}[/itex] for part b. Is the book wrong or have I missed a factor of 1000 somewhere?
Is the Book's Photon Calculation Off by a Factor of 1000?
In summary, the conversation discusses a discrepancy between the answer given in a book and on WolframAlpha for a math problem. The conclusion is that the book has the wrong answer. The conversation also addresses a question about the meaning of "frequency" in relation to photons and concludes that the two concepts are not the same. The question is posed to clarify the math perspectives of the problem.
Part a) is correct, but the book gives me an answer of [itex]2.3*10^{23}[/itex] for part b. Is the book wrong or have I missed a factor of 1000 somewhere?
- #2
mfb
Mentor
- 37,138
- 13,982
WolframAlpha gives 2.27*1020 as well.
- #3
Fluxthroughme
- 71
- 0
mfb said:
I'm going to have to conclude the book has the wrong answer, then. Thanks :)
- #4
Naty1
- 5,606
- 40
goo job...
What did you conclude regarding question [c]?
What did you conclude regarding question [c]?
- #5
Fluxthroughme
- 71
- 0
Naty1 said:
The answer is no, they are not the same. I am not 100% sure why it is even asking this. As far as I can venture a guess, I would say that the word 'frequency' would make some people think of the number of photons emitted per second, and would thus get it confused. However, the frequency of a photon is of A photon, not a bunch of them. Thus, some might think it meant frequency as it "The frequency with which photons are emitted". This clearly isn't the case, though I can understand there is room for confusion.
Would this be correct? As I say, I'm not 100% sure why this is asked; my answer makes sense to me, but it doesn't seem the kind of thing that needs explaining.
- #6
Naty1
- 5,606
- 40
That's basically how I would respond...I think the question just aims at verbalizing the math perspectives.
You can easily change the the number of photons emitted, the power radiated,
by increasing the current. Depending on how you look at it, that would increase
the number of photons but not the frequency...at least as posed in this problem.
In the real world, a hotter bulb likely generates a higher frequency wavelength
AND more photons, but they ARE different concepts as you explain.
You can easily change the the number of photons emitted, the power radiated,
by increasing the current. Depending on how you look at it, that would increase
the number of photons but not the frequency...at least as posed in this problem.
In the real world, a hotter bulb likely generates a higher frequency wavelength
AND more photons, but they ARE different concepts as you explain.
Related to Is the Book's Photon Calculation Off by a Factor of 1000?
1. How is the number of photons per second measured?
The number of photons per second is typically measured using a device called a photometer, which detects and counts individual photons. This measurement is known as the photon flux.
2. What factors affect the number of photons per second?
The number of photons per second can be affected by several factors, including the intensity of the light source, the wavelength of the light, and the distance between the source and the detector.
3. Can the number of photons per second be converted to energy?
Yes, the number of photons per second can be converted to energy by multiplying it by the energy of each photon. This is known as the photon energy flux.
4. How does the number of photons per second relate to the brightness of a light source?
The number of photons per second is directly related to the brightness of a light source. A higher number of photons per second indicates a brighter source, while a lower number indicates a dimmer source.
5. What applications use the concept of number of photons per second?
The concept of number of photons per second is used in various fields such as astronomy, photography, and telecommunications. It is also important in understanding the behavior of light in different environments, such as in quantum mechanics and optics.
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