How can I calculate the number of photons with this data?

In summary, the radio station emits electromagnetic wave with a frequency of 100MHz (102*106 Hz). A visible radiation/glow with a wavelength of 600nm (6*102*10-9 m) has an energy of 3,315*10-19 J. The problem with the question is that i came up with this formula: N=t(h*f/P) where N is the number of the photons and P the power. Does this formula make sense? The higher the power, the fewer the number of photons you get.
  • #1
HazyMan
51
3
The problem says: A radio station emits electromagnetic wave with a frequency of 100MHz (102*106 Hz).
a)What's the energy of this radiation's/glow's photon? (Solved, i found 6,63*10-26 J)
b)Compare your calculation with the energy of another visible radiation/glow, with a wavelength of 600nm (6*102*10-9 m). (Solved as well, found 3,315*10-19 J)
c) and the part that BUGS me, FIND THE NUMBER OF PROTONS EMITTED IN 1 SECOND, IF THE RADIATED/GLOWED POWER IS 6,63kW (6,63*103 W)

The problem with this question is that i came up with this formula: N=t(h*f/P) where N is the number of the photons and P the power. Using this i came up with 10-37 which confuses me, because my teacher had used a different way and found 1029. He took the E=pt formula and turned it into E=N*Ep (Ep is the photon energy that was calculated in question a) and then he created a N=E/Ep [or N=(P*t/Ep)] where he got HIS result from. Can anyone help me? I'm confused.

OTHER EQUATIONS USED: Ep=hf, f2=Co/λο (where f2 is the freq. of the other radiation/glow from question b), Ep2=hf2 (where Ep2 is the photon energy of the other radiation/glow from question b).
 
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  • #2
HazyMan said:
The problem with this question is that i came up with this formula: N=t(h*f/P) where N is the number of the photons and P the power.
Does this formula make sense? The higher the power, the fewer the number of photons you get.
 
  • #3
DrClaude said:
Does this formula make sense? The higher the power, the fewer the number of photons you get.
Well I'm not sure. From a video that I've seen someone mentioned this formula: P=(N*h*f/t) so by replacing the symbols with numbers, i concluded to the N=t(h*f/P) formula.
 
  • #4
HazyMan said:
Well I'm not sure. From a video that I've seen someone mentioned this formula: P=(N*h*f/t) so by replacing the symbols with numbers, i concluded to the N=t(h*f/P) formula.
The formula is correct: P=(N*h*f/t). hf is the energy of 1 photon, to multiplying by N gives you the total energy, dividing by time gives you the power.

The problem is that you have not rearranged the terms correctly.
 
  • #5
DrClaude said:
The formula is correct: P=(N*h*f/t). hf is the energy of 1 photon, to multiplying by N gives you the total energy, dividing by time gives you the power.

The problem is that you have not rearranged the terms correctly.
Oh my, well i should try again.
 
  • #6
DrClaude said:
The formula is correct: P=(N*h*f/t). hf is the energy of 1 photon, to multiplying by N gives you the total energy, dividing by time gives you the power.

The problem is that you have not rearranged the terms correctly.

Is P=(N*h*f/t) equal to P=N(h*f/t) ?
 
  • #7
Alright, i managed to get the same result my teacher did by using a different method. I used the formula: N=P/(hf/t)

In LaTeX: [tex]N=P/(hf/t)[/tex]
 
  • #8
HazyMan said:
Alright, i managed to get the same result my teacher did by using a different method. I used the formula: N=P/(hf/t)

In LaTeX: [tex]N=P/(hf/t)[/tex]
That's the correct equation.
 
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Related to How can I calculate the number of photons with this data?

1. How do I determine the number of photons from a given set of data?

To calculate the number of photons from a set of data, you will need to know the energy of each individual photon, which can be calculated using the equation E=hc/λ, where h is Planck's constant and c is the speed of light. Once you have determined the energy of each photon, you can divide the total energy of the data by the energy of each photon to obtain the number of photons.

2. What information do I need to have in order to calculate the number of photons?

In order to calculate the number of photons, you will need to have data on the total energy of the system or the energy of each individual photon. This information can be obtained through measurements or provided in the data set.

3. Can I use this method to calculate the number of photons for any type of data?

Yes, this method can be used to calculate the number of photons for any type of data as long as you have the necessary information on the energy of the photons. However, the accuracy of the calculation may vary depending on the quality of the data and the assumptions made.

4. Is there a more accurate way to calculate the number of photons?

There are various methods for calculating the number of photons, each with their own advantages and limitations. Some methods may be more accurate in certain scenarios, so it is important to carefully consider the data and choose the appropriate method for your specific situation.

5. Can I use this calculation to compare the number of photons between different systems?

Yes, this method can be used to compare the number of photons between different systems as long as the energy of the photons is consistent. However, it is important to note that the number of photons alone may not provide a complete understanding of the system and other factors should also be considered.

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