Answer:
Explained below
Step-by-step explanation:
In physics, we know that waves usually change direction when are refracted or when they penetrate layers with different densities.
Therefore, when a seismic wave penetrates penetrates the boundary of the earth's interior, part of it will be sent back and part will be transmitted into the medium as refraction occurs. When we record the reflected and refracted ray, it enables the calculation of the position of major boundaries in the Earth's interior. This also helps in providing information about the solid & liquid character as well physical properties of the various layers in the medium.