1. Entering the Glass Block
* Refraction: The light ray bends as it enters the glass block. This bending is called refraction. The reason for this bending is that light travels slower in glass than in air.
* Angle of Incidence and Angle of Refraction: The angle at which the light ray hits the surface of the glass is called the angle of incidence. The angle at which the light ray bends inside the glass is called the angle of refraction. The relationship between these angles is governed by Snell's Law:
* n₁ sin θ₁ =n₂ sin θ₂
* where n₁ and n₂ are the refractive indices of the two media (air and glass) and θ₁ and θ₂ are the angles of incidence and refraction, respectively.
* Normal: An imaginary line perpendicular to the surface of the glass at the point where the light ray enters. The angles of incidence and refraction are measured relative to this normal.
2. Inside the Glass Block
* Straight Line: The light ray travels in a straight line within the glass block.
* Velocità: The speed of light is slower in glass than in air.
3. Leaving the Glass Block
* Refraction Again: When the light ray exits the glass block and enters air, it bends again, this time away from the normal.
* Angle of Emergence: The angle at which the light ray exits the glass block is called the angle of emergence.
* Reversal of Bending: The light ray bends in the opposite direction to how it bent when entering the glass, so the angle of emergence is equal to the angle of incidence.
Important Points:
* The amount of bending depends on the refractive index of the glass. Higher refractive index means greater bending.
* If the light ray enters the glass at a 90° angle (perpendicular to the surface), there is no refraction. It will pass straight through.
* The light ray may also be partially reflected at the surface when it enters and leaves the glass. The amount of reflection depends on the angle of incidence.
Let me know if you'd like a diagram to illustrate this, or if you have any further questions!
