Final answer:
Elasticity is the property that allows a medium to return to its original state after being disturbed, which plays a part in the reflection of waves at a boundary in a medium.
Step-by-step explanation:
- The ability of a medium to bounce back after being disturbed is known as elasticity. This property describes the tendency of particles within a medium to return to their original position when perturbed.
- When a wave encounters the boundary of a medium, one outcome is reflection, where the wave is reflected and known as the reflected wave in contrast to the incident wave that hits the boundary.
- The concept of acoustic impedance is also relevant as it relates to reflections at boundaries between two different media; it is defined by the density of the medium and the speed of sound through the medium, affecting how much of the wave is reflected or transmitted.