The Reflection of Light

Law of Reflection The angle of reflection equals the angle of incidence. Both angles are measured from an imaginary line (normal) that is at a 90° angle from the reflecting surface.

Diagram of the Law of Reflection

Practice Problem One: If a ray of light hits a mirror at 95°, what angle will the reflected ray be? Answer: 95° since the reflected ray has the same angle as the incident ray.

How we see objects in a mirror:

How we see objects in a mirror: The incident ray of light from the object hits the mirror and reflects off at the same angle. The reflected ray hits our eye. Our brain decides that the light came from a point along the reflected ray.

How we see objects in a mirror: This allows us to see the object in the correct position where all of the reflected rays converge.

Curved Mirrors Mirrors that are not flat obey the Law of Reflection, but act as multiple mirrors. This is why curved mirrors can make objects appear smaller or larger.

Diffuse Reflection Most surfaces reflect electromagnetic waves in all different directions. This is beneficial in most circumstances since light reflection would make vision difficult.

Polished Surfaces When the distance between the highpoints on an object are less than 1/8 of the wavelength of light, the object is polished and will reflect the wave.