A 75 W light source consumes 75 W of electric power. Typically only about 5% of this energy is emitted as visible light of wavelength 600 nm. (a) Calculate the frequency of the emitted visible light. (b) How many photons per second of visible light does the source emit? (c) Is the frequency of light the same thing as as the number of photons emitted per second?

Question

A 75 W light source consumes 75 W of electric power.  Typically only about 5% of this energy is emitted as visible light of wavelength 600 nm.  (a) Calculate the frequency of the emitted visible light. (b) How many photons per second of visible light does the source emit?  (c) Is the frequency of light the same thing as as the number of photons emitted per second?

HELP please!

bobpursley · Answer

What is your question? I will be happy to critique your thinking or work, but not so happy to do it for you.

J · Answer

I don't know how to get the frequency, I think if I can figure that out I could get the rest, but I am not sure where the two 75 W come in and the 5% like where am I suppose to put them in any equation?

bobpursley · Answer

You get the frequency from the wavelength.