1. Refraction and the Normal:
* Refraction is the bending of light as it passes from one medium to another. This bending occurs because light travels at different speeds in different materials.
* The normal is an imaginary line perpendicular to the surface at the point where the light ray enters the second medium.
2. The Angle of Incidence and Refraction:
* The angle of incidence is the angle between the incoming light ray and the normal.
* The angle of refraction is the angle between the refracted light ray and the normal.
3. Perpendicular Incidence:
* When light enters perpendicularly, the angle of incidence is 0 degrees.
* Snell's Law governs the relationship between the angles of incidence and refraction, and the refractive indices of the two media:
* n1 * sin(θ1) = n2 * sin(θ2)
* Where n1 and n2 are the refractive indices of the first and second mediums, respectively, and θ1 and θ2 are the angles of incidence and refraction.
4. No Bending:
* Since the angle of incidence is 0 degrees, sin(θ1) = 0.
* For the equation to hold true, sin(θ2) must also be 0. This means the angle of refraction (θ2) is also 0 degrees.
* A 0-degree angle of refraction means the light ray continues traveling straight through the second medium without changing direction.
In Conclusion:
When light enters a second medium perpendicularly, there is no change in its direction because the angle of incidence is 0 degrees, resulting in a 0-degree angle of refraction. This means the light ray continues traveling in a straight line.
