Which phenomenon describes the bending of waves as they transition from one medium to another due to a speed change?

The phenomenon that describes the bending of waves as they transition from one medium to another due to a change in speed is known as refraction. This occurs because waves travel at different speeds in different media. For example, light waves travel more slowly in water than in air, causing them to change direction when they enter the water from air. This bending effect is widely observable in various contexts, such as the optical effects seen when a straw appears bent in a glass of water or when light rays bend as they pass through lenses.

Refraction is crucial in various practical applications, including the design of optical instruments like glasses and cameras, where controlling light paths is essential for focusing and clarity. The change in direction of waves according to Snell's Law precisely characterizes this process, demonstrating how the angle of incidence and the refractive indices of the two media involved dictate the degree of bending that occurs.

This understanding of refraction is essential in fields such as physics and engineering, where it plays a fundamental role in wave behavior.