Light of wavelength 600 nm passes though two slits

Chapter 33, Problem 33.88

(choose chapter or problem)

Light of wavelength 600 nm passes though two slits separated by 0.20 mm and is observed on a screen 1.0 m behind the slits. The location of the central maximum is marked on the screen and labeled y = 0. a. At what distance, on either side of y = 0, are the m = 1 bright fringes? b. A very thin piece of glass is then placed in one slit. Because light travels slower in glass than in air, the wave passing through the glass is delayed by 5.0 * 10-16 s in comparison to the wave going through the other slit. What fraction of the period of the light wave is this delay? c. With the glass in place, what is the phase difference f0 between the two waves as they leave the slits? d. The glass causes the interference fringe pattern on the screen to shift sideways. Which way does the central maximum move (toward or away from the slit with the glass) and by how far?