Very simple double slit question.

[linuxux]

1. The problem statement, all variables and given/known data
500 nm light passes through 2 slits. Nodal lines are produced 3.0 m away. the distance from the 1st to 10th nodal line is 5.0cm. what is the slit separation?


2. Relevant equations

What equation do i use here?

is it this:

http://www.studyphysics.ca/20/unit4/wavemodel/doubleslit/note_files/image015.gif

l = wavelength of light used (m) = 5 x 10^-7

x = distance from central fringe (m) = .05m

d = distance between the slits (m) = ?

n = the order of the fringe = 10

L = length from the screen with slits to the viewing screen (m) = 3.0m

[andrevdh]

Correct, except I think that the "order" should be 9. The first line forms with no difference at all, so its order is 0, and the "order" of the 10th line is therefore 9.

[linuxux]

thanks, thats the part i was confused about.