1. The problem statement, all variables and given/known data 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 2. Relevant equations m = d(sinθ)/λ y=Ltanθ 3. 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!