A laser pointer emits a ray which enters a quartz crystal at an angle 50° with the normal to the surface of the crystal. The ray bends inside the crystal, making an angle of 30° with the normal. Find the index of refraction of quartz.

Light shines from a laser in air down into water. If the laser beam in air makes an angle of $40°$ with the water's surface, what angle will it make with the surface under water?

A graduated cylinder is filled with $14\mathrm{cm}$ of oil floating on $20\mathrm{cm}$ of water. How long, in nanoseconds, does it take light to travel from the top of the oil to the bottom of the water?

A light ray, moving in air, is incident on a piece of plastic at an angle of 23° with respect to the normal. Inside the plastic the ray travels at an angle of 16° with respect to the normal. What is the index of refraction of the plastic?

If oil is floating on water, what is the critical angle at the oil/water boundary?

What is the frequency of an electromagnetic wave that has the same wavelength as a 2.5 kHz sound wave in water?

A helium-neon laser beam has a wavelength in air of 633 nm. It takes 1.38 ns for the light to travel through 30 cm of an unknown liquid. What is the wavelength of the laser beam in the liquid?

Some modern optical devices are made with glass whose index of refraction changes with distance from the front surface. FIGURE P16.72 shows the index of refraction as a function of the distance into a slab of glass of thickness L. The index of refraction increases linearly from n₁ at the front surface to n₂ at the rear surface.b. Evaluate your expression for a 1.0-cm-thick piece of glass for which n₁ = 1.50 and n₂ = 1.60.