* No refraction: The light ray does not bend. It passes straight through the glass block without changing direction.
* Partial reflection: A small portion of the light will be reflected back from the surface of the glass block. This reflected ray will also be at 90 degrees to the surface.
* Transmission: The majority of the light will continue through the glass block, undergoing a slight change in speed.
Here's why this happens:
* Normal Incidence: When the light hits the glass at 90 degrees, it strikes the surface perpendicularly. This means the angle of incidence (the angle between the incoming light ray and the normal line to the surface) is 0 degrees.
* Snell's Law: Snell's Law describes the relationship between the angle of incidence, the angle of refraction, and the refractive indices of the two mediums (air and glass). At 90 degrees, the angle of incidence is 0, and the sine of 0 degrees is 0. This means the angle of refraction is also 0 degrees, resulting in no bending of the light ray.
In summary: At normal incidence, a ray of light passing through a glass block experiences minimal change in direction, with only a small portion being reflected back.
