Reflection Flashcards
What is reflection?
When a wave is reflected at (bounces off) the boundary between 2 different materials.
What can happen to waves at the boundary of 2 different materials?
. reflection
.absorption
. transmission
What is the law of reflection?
angle of incidence = angle of reflection
What causes echoes?
the reflection of sound
What is the normal?
an imaginary line at 90 degrees (perpendicular) to the surface at the point of incidence (where the wave hits the boundry)
What is the angle of incidence?
the angle between the incoming wave and the normal
What is the angle of reflection?
The angle between the reflected wave and the normal
The normal is usually shown as a dotted line
The smoother the surface
the stronger the reflected wave
What happens in specular reflection?
a wave is reflected in a single direction by a smooth, flat surface e.g. reflection in a mirror
What do you get as a result of specular reflection?
A clear reflection - as a result the surface appears shiny
How are the waves reflected on a smooth surface/in specular reflection?
all the waves bounce off the boundary at the same angle.
How will light interact with an opaque object in terms of reflection?
Light will reflect if the object is opaque (it isn’t absorbed by the material) - the electrons will absorb the light energy then re emit it as a reflected wave.
When light is reflected by a rough surface, the surface appears matte.
in a specular reflection image, the rays appear to diverge from behind the mirror so the image appears to come from behind the mirror
What is diffuse reflection?
When a wave is reflected by a rough/ uneven surface and the reflected rays are scattered in lots of different directions
Why does diffuse reflection occur?
the normal is different for each incoming ray meaning that the angle of incidence is different for each ray - the rule still applies angle of incidence = angle of reflection hence the angle of reflection also being different for each ray
What will this scattering of light cause?
a distorted image or no image at all
How does glass react with IR radiation?
It reflects IR radiation.
