Bright Fringes (Intro to Quantum Physics Qestion?)


by megaoka
Tags: bright, fringes, intro, physics, qestion, quantum
megaoka
megaoka is offline
#1
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
xm=mλL/d


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:
Spoiler
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!
Cheers,
~a distressed AP student
Phys.Org News Partner Science news on Phys.org
Lemurs match scent of a friend to sound of her voice
Repeated self-healing now possible in composite materials
'Heartbleed' fix may slow Web performance
dx
dx is offline
#2
Apr21-09, 02:12 AM
HW Helper
PF Gold
dx's Avatar
P: 1,962
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.
megaoka
megaoka is offline
#3
Apr21-09, 09:56 AM
P: 2
d=0.5mm L=2.5m λ=580nm
xm=mλL/d

x=(1)(580x10^-9)(2.5)/(0.5x10^-3)=.0029
Okay!

Thanks! I got my answer.


Register to reply

Related Discussions
How many bright fringes are seen in the reflected light Introductory Physics Homework 4
RE:bright fringes.. Introductory Physics Homework 6
Distance between m=0/m=1 bright fringes Introductory Physics Homework 1
Intro to quantum physics Quantum Physics 2
Intro to Quantum Physics questions... Advanced Physics Homework 6