Answer:
See explanation
Explanation:
1) There are two main types of waves;
Mechanical waves and electromagnetic waves.
Mechanical waves usually require a medium for propagation, e.g sound, waves on a spiral spring, etc
Electromagnetic waves do not require a medium for propagation e.g microwaves, x-rays etc
2) The phenomenon is known as refraction. Refraction occurs at the boundary between two media because of the change in the speed of a wave as it moves from one medium to another.
