1. The problem statement, all variables and given/known data In a classroom demonstration, a beam of coherent light of wavelength 550 nm is incident perpendicularly onto a pair of slits. Each slit has a width w of 1.2 x 10^-6 m, and the distance d between the centers of the slits is 1.8x10^-5 m. The class observes light and dark fringes on a screen that is a distance L of 2.2 m from the slits. Your notebook shows the following setup for the demonstration. See page 11: http://apcentral.collegeboard.com/apc/public/repository/ap09_frq_physics_b.pdf (a) Calculate the frequency of the light. (b) Calculate the distance between two adjacent dark fringes on the screen. The entire apparatus is now immersed in a transparent fluid having index of refraction 1.4. (c) What is the frequency of the light in the transparent fluid? (d) Does the distance between the dark fringes increase, decrease, or remain the same? _____ Increase _____ Decrease _____ Remain the same Explain your reasoning. 2. Relevant equations f = c/[tex]\lambda[/tex] ydark = [[tex]\lambda[/tex]L/d][m+.5] 3. The attempt at a solution A) f = c/[tex]\lambda[/tex] f = (3.0*10^8 m/s)/(5.5*10^(-7) m) = 165Hz B) ydark = [[tex]\lambda[/tex]L/d][m+.5] Hmm... would you have to find a [tex]\Delta[/tex]y, though? How would you do this?