Calculating Photon Emission and Threshold Wavelengths

[Antnorwe]

Hey. I have 2 questions I'm having a bit of trouble with, here they are:

1. The average energy of the photons emitted by the light bulb in the visible region is 2 eV. Calculate the number of these photons received per square metre per second at this distance from the light bulb.

Distance = 2m
Intensity at this point = 0.095w/m(2)

2. Calculate the threshold wavelength for a metal surface which has a work function of 6.2 eV. (In relation to the Photoelectric Effect)

Any help would be greatly appreciated :)

Cheers.

 

[G01]

You need to show some work to get help in this forum.

Show me some calculations or thoughts on the problem, so I am able to know more of what exactly is stumping you.

 

[Antnorwe]

Well for both questions I am unfamiliar with the formula required to work out the answer.

 

[G01]

I'm sorry if I sound mean, I am not trying to. I can give you the formulas but you can look those up yourself easily enough. Do you want someone else to look up the formulas for you? This falls under the category of doing the work for you, which we do not do here.

You have definitely discussed the relationship between power and energy if you are talking about photons and the photoelectric effect. Also, the relationship needed in the second question is definitely discussed in the photoelectric effect section of your text.

All I am saying is that you haven't even given any of your own thoughts on the problem, nor even tried listing the formulas and relationships involved. This is not the way to get help here. You have to show some independent thought and effort. Those are the rules.

So here's my suggestion. If you haven't yet, read the section in the text that covers the material involved in these problems. After you have done that, then at least give me some thoughts on the problem. Give me some effort. Tell me what formulas or concepts you THINK are involved, etc. You must know something about the concepts and relationships involved here.