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

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Homework Help Overview

The discussion revolves around calculating the number of photons emitted by a radio station with a given power output and frequency. The original poster presents a problem involving electromagnetic radiation, specifically focusing on the energy of photons and the relationship between power and photon emission.

Discussion Character

  • Exploratory, Mathematical reasoning, Assumption checking

Approaches and Questions Raised

  • Participants explore different formulas to calculate the number of photons, questioning the validity of their approaches and the relationships between power, energy, and photon count. There is discussion about rearranging equations and the implications of power on the number of photons emitted.

Discussion Status

Multiple interpretations of the formulas are being explored, with some participants expressing confusion about the correct rearrangement of terms. There is a recognition that different methods can yield the same result, and some guidance has been offered regarding the relationships between the variables involved.

Contextual Notes

Participants are working under the constraints of a homework assignment, which may impose specific methods or approaches to problem-solving. There is an emphasis on understanding the underlying physics rather than simply arriving at a numerical answer.

HazyMan
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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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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.
 
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.
 
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.
 
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.
 
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) ?
 
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: N=P/(hf/t)
 
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: N=P/(hf/t)
That's the correct equation.
 
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