1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Which formulas are appropriate for calculating intensity?

  1. Aug 4, 2017 #1
    1. The problem statement, all variables and given/known data
    Monochromatic plane waves of wavelength 537nm are incident on two narrow slits and produce an interference pattern on a wall 3.1m away. The slits are spaced 26 micrometers apart and are 5.7 micrometers wide each. What is the ratio of intensity to that of the central fringe a distance of 35.5mm from the central fringe?



    2. Relevant equation

    I=I0(cos(∏(d/(λL)z))


    3. The attempt at a solution

    I tried using this formula to find the intensity of the central fringe and also the intensity of the fringe 35.5mm from the central fringe, however, I could not determine what I(sub)naught was.
     

    Attached Files:

  2. jcsd
  3. Aug 4, 2017 #2

    Charles Link

    User Avatar
    Homework Helper

    Your formula is correct, as you have it in the link. You left out the exponent of 2 when you typed it out. They simply want you to compute the ratio ## \frac{I}{I_o} ##. You should be able to do that using your formula. (Usually the letter ## x ## is used instead of ## z ## in this formula. In any case, ## z=35.5 ## mm). You should be able to figure out what ## d ##, ## L ## and ## \lambda ## are.
     
    Last edited: Aug 4, 2017
  4. Aug 4, 2017 #3
    That makes so much sense! Thanks a lot for your time!
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted



Similar Discussions: Which formulas are appropriate for calculating intensity?
  1. Which formula? (Replies: 1)

  2. Which formulae? (Replies: 6)

  3. Calculating intensity (Replies: 1)

Loading...