A laser is used to illuminate a diffraction grating that has spacing of 637 lines per mm. The grating sits 11.6 cm in front of a screen. Find the distance to the first and second maxima (y1 and y2) for the laser wavelength of 643 nm. Express your answers in mm.
wavelength = (s/m)(ym/sqrt(L2+ym2))
The Attempt at a Solution
s = 1/637 = .00156 mm
L = 116 mm
wavelength = 643 X 10-6 mm
I tried solving this equation for ym, but the answer I got was wrong. Is there another way to do this problem?