SP 212 Worksheet
Lesson 37: Ch. 35.1-35.2, Light as a Wave
1) How fast does light travel through water (nwater = 1.33)?
2) Two beams of light, each with wavelength λ = 581 nm, are traveling in air and are initially in phase. One
passes through a layer of glass (n = 1.65) that has thickness L. The other passes through a layer of plastic
(n = 1.46) of the same thickness. What is the smallest value of L (besides L = 0) that results in the beams
being perfectly in phase upon exiting the layers?
3) The slits in a double-slit arrangement are separated by a distance equal to 80× the wavelength of the light
passing through them (d = 80λ). a) What is the angular separation between the central maximum and an
adjacent maximum in the interference pattern? b) What is the distance between these maxima on a screen
that is 52.5 cm from the slits?