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kevnm67
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Homework Statement
A diffraction grating with 620 lines per mm is illuminated with light of wavelength 520 nm. A very wide viewing screen is 2.0 m behind the grating. (Note: 1 mm = 10-3 m; 1 nm =10-9 m)
a) What is the distance between the two m=1 bright fringes? (Express your answer in meters)
b) How many bright fringes can be seen on the screen
Homework Equations
m = d(sinθ)/λ
y=Ltanθ
The Attempt at a Solution
A)
d(sinθ)=mλ
=sin-1 (1x(520x10-9)/(1/620 x10-3))
=18.81
y=Ltanθ
tan(18.81)x2
=.34
.34 x 2 x 2 = 1.36 meters
B) ?
m = d(sinθ)/λ
but when I use this equation I do not get the correct answer. I am at a loss if someone can walk me through this part.
Thanks!