Number of photons emitted from a laser

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To determine the number of photons emitted by a 35mW laser producing 526nm green light, the energy of one photon must first be calculated using the formula E=hf, where h is Planck's constant and f is the frequency derived from the wavelength. The user initially struggled with the concept and sought clarification, noting that their textbook lacked sufficient information on the photoelectric effect and related equations. After receiving assistance, the user successfully solved the problem. The final answer for the number of photons emitted each second is 1.9×10^18. Understanding the relationship between energy, frequency, and wavelength is crucial in photon calculations.
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Homework Statement


A 35mW laser produces 526nm green light.
What is the number of photons it emits each second?
1.9×1017
1.9×1018
1.0×1017
9.3×1016


Homework Equations





The Attempt at a Solution


I've been playing with E=hf and lambda = h/p ----- no success!
The textbook I am using doesn't have much on photons/photoelectric effect - nothing that helps me with this question at least. the "photon wavelength-momentum relation" is I think the most relevant to this question?? The textbook doesn't actually say what p is so I assumed number of photons but that's wrong since it doesn't work.

anyway need some help please.
 
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Calculate the energy of one photon. You need to get the frequency from the wavelength.

ehild
 
thanks ehild - solved the problem
 

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