* Change in Speed: When a wave travels from one medium to another, its speed changes. This is because the wave interacts differently with the particles of each medium. For example, light travels slower in water than in air.
* Angle of Incidence: The angle at which the wave strikes the boundary between the two media is called the angle of incidence.
* Angle of Refraction: The angle at which the wave travels in the second medium is called the angle of refraction.
* Snell's Law: The relationship between the angle of incidence, the angle of refraction, and the speeds of the wave in the two media is described by Snell's Law:
```
n1 * sin(θ1) = n2 * sin(θ2)
```
where:
* n1 is the refractive index of the first medium
* n2 is the refractive index of the second medium
* θ1 is the angle of incidence
* θ2 is the angle of refraction
* Refraction Explained: When a wave enters a medium where it travels slower, it bends towards the normal (an imaginary line perpendicular to the boundary). This is because the portion of the wave that enters the slower medium first slows down, while the portion still in the faster medium continues at its original speed. This difference in speed causes the wave to bend.
Examples of Refraction:
* Light passing through a prism: A prism bends different wavelengths of light at different angles, creating a rainbow.
* Water appearing shallower than it is: When you look at an object underwater, it appears higher than it actually is because light bends as it passes from water to air.
* Lenses in eyeglasses and cameras: Lenses use refraction to focus light.
Key Points to Remember:
* Refraction occurs because of a change in the wave's speed as it moves from one medium to another.
* The amount of bending depends on the angle of incidence and the refractive indices of the two media.
* Refraction is a fundamental phenomenon that affects the way we see and interact with the world around us.
