Easy question on diffraction of light

[Sabrina_18]

[SOLVED] Easy question on diffraction of light please help!

Homework Statement

Wavelengths are; 1 - 520nm
Wavelength 2 - 520.8nm
Diffraction grating - 400 lines per mm
How many orders will the lines be seen in?

Homework Equations

N = dsin0/lamda

The Attempt at a Solution

d = 1/4 X 10^5 = 25 X10^-7m
25 X 10^-7 / 520 X 10^-9 = 4.8
So is the answer 4? for the first wavelength (520nm)

 

[G01]

Your work looks good to me.

 

[Kaleb]

I got 4.80769, so your math is correct.

 

[Sabrina_18]

Thanks - hope its right!