In Fig. $35\mathrm{.}1\mathrm{.}4,$ the two light waves that are represented by the rays have wavelength $550\mathrm{.}0$ nm before entering media $1$ and $2.$ They also have equal amplitudes and are in phase. Medium $1$ is now just air, and medium $2$ is a transparent plastic layer of index of refraction $1\mathrm{.}600$ and thickness $2\mathrm{.}600m.$

a$.$ What is the phase difference of the emerging waves in wavelengths, radians, and degrees? What is their effective phase difference $($in wavelengths$)?$

b$)$ If the waves reached the same point on a distant screen, what type of interference would they produce?