This question is about the propagation of light through different materials.
A ray of light is directed inside a semicircular polymer block towards the center of its flat face, which is exposed to the air.
Under certain conditions, the light ray does not cross into the air but is reflected entirely back into the polymer. (i) State the name of this phenomenon. (ii) If the angle of incidence of this ray at the polymer-air boundary is 58∘58^\circ58∘, state the angle of reflection.
The path of the incident ray is now adjusted so that the light exits the polymer block and enters the air. (i) Describe how the direction of the ray changes as it passes across the boundary from the polymer to the air. (ii) State the name of this process.
(i) State the equation linking the critical angle, ccc, and the refractive index, nnn, for a boundary between a medium and air. (ii) The refractive index of this high-index polymer is 1.671.671.67. Calculate the critical angle for the boundary between the polymer and air. Give your answer to three significant figures. (iii) The light source is repositioned so that the ray of light is incident on the polymer-air boundary at an angle of 35∘35^\circ35∘. Explain what happens to this ray of light.