1. Different Speeds:
* Different media have different densities. Denser media generally cause light to travel slower than less dense media. For example, light travels slower in water than it does in air.
* The change in speed affects the wave's direction. When a wave enters a denser medium at an angle, the part of the wave that enters first slows down before the rest of the wave. This difference in speed causes the wave to bend.
2. Angle of Incidence:
* The angle at which the wave hits the boundary between the two media is called the angle of incidence. The greater the angle of incidence, the more the wave will bend.
3. Snell's Law:
* The relationship between the angle of incidence, the angle of refraction (the angle at which the wave bends), and the speeds of light in the two media is described by Snell's Law:
* n₁sinθ₁ = n₂sinθ₂
* n₁ and n₂ are the refractive indices of the two media (a measure of how much light slows down in each medium).
* θ₁ is the angle of incidence.
* θ₂ is the angle of refraction.
In summary, refraction occurs because the change in speed of the wave as it enters a new medium causes the wavefront to bend. This bending is dependent on the angle of incidence and the difference in the refractive indices of the two media.
