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Slit & light interference 
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#1
Jan3113, 10:57 AM

P: 91

1. The problem statement, all variables and given/known data
Two narrow slits are cut into a sheet of paper and set in front of a laser beam, causing an interference pattern to appear on the wall. If the distance from one slit to the third bright fringe is 0.5000004 m and the distance from the other slit to the same bright fringe is 0.5000008 m calculate the wavelength of the light from the laser. 2. Relevant equations  P_{m}S_{1}  P_{m}S_{2} = m[itex]\lambda[/itex] 3. The attempt at a solution My answer: 0.50000040.5000008=(3)[itex]\lambda[/itex] 0.0000004/3 = [itex]\lambda[/itex] [itex]\lambda[/itex] = 0.000000133 m edit: my answer uses  P_{3}S_{1}  P_{3}S_{2} whereas the book's answer uses  P_{m}S_{1}  P_{m}S_{2} How would I turn one into the other? The book's answer: 0.500000300.50000165=3[itex]\lambda[/itex] [itex]\lambda[/itex]=0.00000135/3 [itex]\lambda[/itex]=0.00000045m = 450nm I'd like to know where they got the values of: P_{m}S_{1}=0.50000030m and P_{m}S_{2}=0.50000165m 


#2
Jan3113, 11:03 AM

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#3
Jan3113, 11:04 AM

P: 91

didn's leave anything out :/
sorry, i edited my original post a second ago. edit: my answer uses  P3S1  P3S2 whereas the book's answer uses  PmS1  PmS2 How would I turn one into the other? 


#4
Jan3113, 11:09 AM

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PF Gold
P: 4,887

Slit & light interference



#5
Jan3113, 11:14 AM

P: 91

sorry, corrected the mistake.
the book has been known to make errors in their solutions... but i was wondering if there's something i'm missing 


#6
Jan3113, 11:26 AM

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PF Gold
P: 4,887

I think your work is correct.



#7
Jan3113, 11:27 AM

P: 91

alright, thanks



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