Adiffraction grating is ruled with 100,000 lines in a distance of 8 cm and used in the first order to study the hyperfine structure of a spectral line at 423 nm. how does the chromatic resolving power compare to that of a equilateral glass prism with a base of 8 cm and refractive indices of 1.5608 at 401nm and 1.5462 at 445 nm? assume the grating was ruled with a blaze to create maximum efficiency at 423 nm (littrow configuration), what is the blaze angle for the ruled grating?

People with normal vision cannot focus their eyes underwater if they aren't wearing a face mask or goggles and there is water in contact with their eyes. in a simplified model of the human eye, the aqueous and vitreous humors and the lens all have a refractive index of 1.40, and all the refraction occurs at the cornea, whose vertex is 2.60 cm from the retina.with the simplified model of the eye, what corrective lens (specified by focal length as measured in air) would be needed to enable a person underwater to focus an infinitely distant object? (be careful-the focal length of a lens underwater is not the same as in air! assume that the corrective lens has a refractive index of 1.62 and that the lens is used in eyeglasses, not goggles, so there is water on both sides of the lens. assume that the eyeglasses are 2.05cm in front of the eye.)