Calculating Minimum Angle in Multiple-Slit Interference

[robera1]

Homework Statement

"If the distance between the centers of adjacent slits in the five-slit mask is 125[lambda], determine the angle (measured relative to the normal to the screen) to the minimum closest to the center of the screen."

Homework Equations

So, I have a question about the homework due tomorrow.
Here is the question:

So, do I use dsin[theta] = m[lambda]?
Where d would be, well, I am not sure,
Theta is what I'd be solving for,
m would be 0.5 (I think, but not sure since there are 5 slits)
and lambda would be 125

Is this right, or totally wrong?

 

[Delphi51]

Correct formula. "d" is the distance between slits, so replace it with 125*L
(I'm writing L instead of lambda). That gives you
125*L*sin(A) = m*L
For the first minimum, m = 1/2.
The L cancels, so you can find A.

 

[robera1]

Okay, so theta = 0.23 degrees?

 

[Delphi51]

Yes, that's it.

 

[robera1]

Awesome! Thanks :D