Which two factors determine the speed of sound through a structure?

The correct answer focuses on density and thickness as the factors that influence the speed of sound through a structure. Sound waves travel through different media at varying speeds depending on the properties of those media.

Density plays a significant role because sound travels faster in denser materials. This is due to the fact that denser materials have closely packed molecules that facilitate the rapid transfer of sound waves. The thicker a material is, it can also influence how sound waves propagate, though the relationship is more nuanced compared to density.

On the other hand, factors like temperature and elasticity (found in other answers) also impact sound speed; temperature affects the kinetic energy of particles and can alter sound speed, while elasticity measures how much a material can deform and return, influencing sound propagation as well. However, in this context, the combination of density and thickness provides a clearer depiction of how sound speed is primarily influenced through a structure.