Question

sound can be transmitted through all of the following except
vacuum
gas
solid
liquid
question #20
substance state index of refraction density (g/ml) speed (m/hr.)
vacuum n/a 0 n/a 675,000,000
air gas 1.0 0.00128 674,533,030
water liquid 1.33 1 506,250,000
glass solid 1.5 2.7 450,000,000
using the table above, what is the best explanation for the relationship between the speed of light and the index of refraction of the substance through which it travels?
as the speed of light increases, density increases.
as the speed of light increases, the index of refraction increases.
as the speed of light increases, the index of refraction decreases.
the index of refraction does not change with the speed of light.

Explanation:

1. For the first question, sound requires a medium to travel. Vacuum is a space devoid of matter, so sound cannot travel through it. Gases, solids, and liquids are all media through which sound can propagate.
2. For the second question, looking at the table, as the speed of light decreases from vacuum to air, water, and glass, the index of refraction increases from 0 to 1.0, 1.33, and 1.5 respectively. So, as the speed of light increases, the index of refraction decreases.

Answer:

1. Vacuum
2. As the speed of light increases, the index of refraction decreases.