1. The problem statement, all variables and given/known data A grating with 3000 lines per cm is used to disperse green light (500nm) and another light of unknown wavelength on a screen 2 m from the grating. The linear separation between the green and unknown light on the screen in the second order is found to be 10 cm. Find the wavelength of the unknown light. 2. Relevant equations [tex]dsin(\Theta) = m\lambda[/tex] [tex]y = m*\lambda*L/d[/tex] 3. The attempt at a solution L = 2 m d = 1/300,000 m y = .1 m I don't know what the answer is but all I can get is 83 nm by doing this: .1 m * 300,000 m / 2m / 2 = [tex]\lambda[/tex] I am guessing it's wrong because it's not visible light. Does anyone know if I did anything wrong? I'm not sure if I need to do something with the given 500 nm.