Suppose that in a situation like that in Example 25.2, light goes from air to diamond and that the incident angle is 30.0°. Calculate the angle of refraction θ₂ in the diamond.

Strategy

Again the index of refraction for air is taken to be n₁ = 1.00, and we are given θ₁ = 30.0. We can look up the index of refraction for diamond in Table 25.1, finding n₂ = 2.419. The only unknown in Snell's law is θ₂, which we wish to determine.

Data from Table 25.1

Data from Example 25.2

Find the index of refraction for medium 2 in Figure 25.12(a), assuming medium 1 is air and given the incident angle is 30.0 and the angle of refraction is 22.0°.

Strategy

The index of refraction for air is taken to be 1 in most cases (and up to four significant figures, it is 1.000). Thus n = 1.00 here. From the given information, θ₁ = 30.0° and θ₂ = 22.0°. With this information, the only unknown in Snell's law is n, so that it can be used to find this unknown.

Data from Figure 25.12

Medium Gases at 0C, 1 atm Air Carbon dioxide Hydrogen Oxygen Liquids at 20C Benzene Carbon disulfide Carbon tetrachloride Ethanol Glycerine Water, fresh Solids at 20C Diamond n 1.000293 1.00045 1.000139 1.000271 1.501 1.628 1.461 1.361 1.473 1.333 2.419