A ray of light in air is incident on the surface of an unknown transparent liquid contained in a large tank. The angle between the incident ray and the normal is 55∘.
(a) State the relationship connecting the angle of incidence, the angle of refraction and the refractive indices of the two media at a plane boundary.
(b) If the refracted ray inside the liquid makes an angle of 34∘ with the normal, calculate the refractive index of the liquid. Give your answer to three significant figures.
(c) Using the value obtained in part (b), determine the speed of light in the liquid.
(d) If light of the same frequency were to travel from this liquid back into air making the same incident angle of 34∘ inside the liquid, find the new angle of refraction in air and verify the principle of reversibility of light.