College Physics 10th Edition by Raymond Serway,Chris Vuille

Exercise 70

Three discrete spectral lines occur at angles of 10.1°, 13.7°, and 14.8°, respectively, in the first-order spectrum of a diffraction-grating spectrometer. (a) If the grating has 3 660 slits/cm, what are the wavelengths of the light (b) At what angles are these lines found in the second-order spectra