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Bright Fringes (Intro to Quantum Physics Qestion?)

by megaoka
Tags: bright, fringes, intro, physics, qestion, quantum
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Apr21-09, 01:24 AM
P: 2
1. The problem statement, all variables and given/known data
The distance between two slits is 0.05mm and the distance to the screen is 2.5m. What is the spacing between the central bright fringe and the first-order fringe? Use yellow light with a wavelength of 580nm

2. Relevant equations

3. The attempt at a solution
L=0.5mm d=2.5m λ=580nm
xm=(1)(580x10-9)/(.5x10-3) = .00116m
(all the numbers were converted to meters)

Whenever I plug these problems in, I get a strange answer that isn't anywhere near the multiple choice answers. What am I doing wrong?

Multiple choice answer possibilities:
a) 0.01m
b) 0.029m
c) 0.29
d) 0.1m
e) 0.6m

I don't want the answer, I want to know what I did wrong here. If you get the right answer, please help!
~a distressed AP student
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Apr21-09, 02:12 AM
HW Helper
PF Gold
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P: 1,961
Hi megoka,

You mixed up L and d. L is the distance to the screen 2.5 m, and d is the space between the slits 0.05 mm.
Apr21-09, 09:56 AM
P: 2
d=0.5mm L=2.5m λ=580nm


Thanks! I got my answer.

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