* Different Speeds: Light travels at different speeds in different mediums. For example, light travels slower in water than in air.
* Angle of Incidence: The angle at which the light ray hits the boundary between the two mediums is called the angle of incidence.
* Angle of Refraction: The angle at which the light ray bends as it enters the new 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 light in the two mediums is described by Snell's Law:
* n₁ sin θ₁ = n₂ sin θ₂
* Where:
* n₁ and n₂ are the refractive indices of the two mediums.
* θ₁ is the angle of incidence.
* θ₂ is the angle of refraction.
Key Points:
* Refraction always occurs when light passes from one medium to another at an angle, unless the light ray hits the boundary perpendicularly.
* The amount of bending depends on the difference in speeds of light in the two mediums and the angle of incidence.
* If the light ray travels from a medium with a higher speed of light to a medium with a lower speed of light, it will bend towards the normal (an imaginary line perpendicular to the surface).
* If the light ray travels from a medium with a lower speed of light to a medium with a higher speed of light, it will bend away from the normal.
Examples of Refraction:
* A straw in a glass of water appears bent: Light from the straw travels through water and then air, causing it to bend and make the straw appear at a different angle.
* A rainbow: Light from the sun is refracted through water droplets in the atmosphere, separating the different wavelengths of light and creating the colors of the rainbow.
Let me know if you'd like a more detailed explanation or have any specific questions about refraction!
