# Homework Help: Youngs Double-Slit Experiment

1. Feb 29, 2012

### lolcheelol

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

In a Young's double-slit experiment, two rays of monochromatic light emerge from the slits and meet at a point on a distant screen, as in the figure below. The point on the screen where these two rays meet is the eighth-order bright fringe. The difference in the distances that the two rays travel is 3.22 10-6 m. What is the wavelength of the monochromatic light?

d=3.22x10^-6
m=8
λ=?

2. Relevant equations

sinθ = mλ/d

3. The attempt at a solution

well i derived the equation
sinθ*d/m = λ

I'm pretty sure I can figure it out once I get the θ, but I have absolutely no idea how to solve for it in this case.

I'm also not sure if you need y=L*tanθ

any help is appreciated

2. Feb 29, 2012

### technician

In the double slit experiment Maxima occur when the path difference between the 2 sources = nλ
That should be all you need !!

3. Feb 29, 2012

### lolcheelol

i dont understand, do u mean

3.22x10^-6/8 = λ