A diffraction grating with 600 lines per millimeter is used in a laboratory to measure the wavelengths of three monochromatic light sources commonly identified as red, green, and blue. For the first‐order (m=1) maxima measured from the central line, the angles from the central maximum to each bright fringe are:
• red beam: 20.1∘
• green beam: 15.2∘
• blue beam: 12.0∘
(a) Determine the wavelength of each light source. Show all work, including the grating spacing you use.
(b) Rank the three wavelengths from longest to shortest.
(c) Using your results, rank the three colors by frequency from lowest to highest and explain how you arrived at your ordering.
(d) Suppose the experiment is repeated for the second‐order maxima (m=2). Predict how the angular separation between the red and blue maxima would compare with that found in the first order, and provide reasoning based on your wavelength results from part (a).