Light of a single color hits the wall after traveling 1.40 m from a small sliver of your window of width 0.600 mm. A diffraction pattern appears on your wall with a central maximum width of 1.15 mm. What is the wavelength of the light

Condition for diffraction maximum is

Here,

d = Distance between slits

m =Order of interference, or any integer which represent the number of repetition of the spectrum

= Wavelength

For small angles we have that

L = Distance of the Screen

y = Position on the screen

At the same time we have that the distance of the edge of central maximum is

Replacing all in the first equation we have

Remember that for the maximum value to be given, then the order of interference must be 1, replacing with the other values we will have to,

Therefore the wavelength of the light is 246.4nm