Which is true about the velocity of sound waves in solids compared to air

Third option; "travels slower in solids because particles are close together"

Explanation: While in the air the particles are very freely and the sound does not need to do a lot of work, in a dense material this is not the case. The particles are more close together, and this causes that in a fixed distance, the sound wave needs to move more particles in a solid than in the air. This makes the sound wave to travel slower when it is in a solid.

answer: the correct answer id option(d).

explanation:

snell's law refraction:

the angle of refraction =

the angle of incidence =

refractive index of air = = 1

refractive index of glycerol = 1.47

from the given options, the most closest answer to 63.72° is 65° of option (d).