Double Slit Interference Question

[iurod]

Homework Statement

Light of wavelength 680 nm falls on two slits and produces an interference pattern in which thefourth-order fringe is 38 mm from the central fringe on a screen 2.0 m away. What is the separationof the two slits?

Homework Equations

Sintheta=2m(\lambda2d)

x=L(\lambda/d

The Attempt at a Solution

My givens are:
\lambda= 680nm
L= 2.0m
x₄38mm

using equation x=L(\lambda/d I got:

0.038 = 2.0m(680 x 10^-9(4)/d)
d=2.0m(680 x 10^-9(4)/d)/0.038)= 1.4x10^-4m

Am I doing this correctly?

Thanks.

 

[collinsmark]

I got:

0.038 = 2.0m(680 x 10^-9(4)/d)
d=2.0m(680 x 10^-9(4)/d)/0.038)= 1.4x10^-4m

Am I doing this correctly?

That's how I did it.

 

[collinsmark]

I got:

0.038 = 2.0m(680 x 10-9(4)/d)
d=2.0m(680 x 10^-9(4)/d)/0.038)= 1.4x10^-4m

Oh, except you left the "/d" in there. But I'm guessing that's just a typo.

 

[iurod]

Thanks! Definitely a typo, sorry about that.