A plane wavefront of wavelength 600nm is travelling in air with speed 3.0×108m s−1. It is incident on a flat glass surface at an angle of 45∘ to the normal. In glass the speed of this light becomes 2.0×108m s−1.
(a) Calculate the angle of refraction in glass.
(b) Determine, to three significant figures, the distance advanced by the wavefront inside the glass in 2.0ns.
(c) On a neat labelled sketch, show the incident and refracted wavefronts along with their normals.