A diffraction grating with 1000 slits/cm is oriented parallel to the y-axis and its center is located on the x-axis at x = -5.00 m. A source of light of wavelength 650 nm is located on the x-axis at x = -125 m. At how many locations does constructive interference occur on the y-axis? Use the symbol N for the number of locations.
For this problem, I used y = m(lambda)L / d. I have d as 10^-5 m, lambda as 650 nm, or 6.5 * 10^-7 m, L = 125 m, and y = 5 m. The answer comes out to 0.615 m, which becomes 1.
Is this correct?