Assume two waves of light in air, of wavelength 681nm, are initially in phase. One travels through a glass layer of index of refraction n1 = 1.46 and thicknessL. The other travels through an equally thick plasticlayer of index of refraction n2 = 1.15. What is the smallest value L in meters should have if the wavesare to end up with a phase difference of 5.75 rad?