Homework Help: Diffraction Problem

jcpwn2004 · May 7, 2008

1. The problem statement, all variables and given/known data

http://img73.imageshack.us/img73/2750/physicsnm5.jpg [Broken]

2. Relevant equations

asinO=m(wavelength)

3. The attempt at a solution

I don't really know where to start...

lzkelley · May 7, 2008

I'm pretty sure this question doesn't make any sense.

alphysicist · May 7, 2008

Hi jcpwn2004,

For part a, they are saying that diffraction effects occurring as the light passes through the pupil can cause the eye to not be able to perceive the individual dots. Would these diffraction effects be greater for larger or smaller wavelengths? Once you know that you can determine the color.

For part b there are some formulas that I think should be derived in your textbook, and those sections would probably be good to read to understand how to use the formulas. Try to find a section titled something like "limiting angle of resolution" or "resolution of apertures", and you will probably find formulas for rectangular and circular apertures. What do you get?

jcpwn2004 · May 7, 2008

the diffraction effects would be less for larger wavelengths, therefore larger wavelengths would blend the fastest? So red would be the first color to blend?

for the 2nd part i have sin0=1.22(wavelength)/D and used 480nm for violet light and got .06 which isn't right :(.

alphysicist · May 7, 2008

It's difficult to tell what you did since you did not show the numbers you plugged in. What numbers did you use, and how did you get the answer of 0.06?

jcpwn2004 · May 7, 2008

alphysicist said: ↑

It's difficult to tell what you did since you did not show the numbers you plugged in. What numbers did you use, and how did you get the answer of 0.06?

I did a=L(wavelength)/Y so .005=L(400nm)/.002 and got L=25m which is off, the final answer should be 20.5

Is my answer for part a correct though?