Suppose you illuminate two thin slits by monochromatic coherent light in air and find that they produce their first interference minima at ±30.00o on either side of the cbf. You then immerse these slits in a transparent liquid and illuminate them with the same light. Now you find that the first minima occur at ±20.00o instead. What is the index of refraction of this liquid?
Two speakers, 4.00 m apart, are driven by the same audio oscillator so that each one produces a sound with a frequency of 1360 Hz. The speed of sound in the room is 340 m/s. Find all the angles relative to the usual center line in front of (and far from) the speakers at which both frequencies interfere (a) constructively. (b) destructively.