Refraction Flashcards
What is refraction?
when the waves change direction as they meet a boundary due to the change in speed because of a change in density
What do waves do when they enter a denser material?
bend towards the normal
What do waves do when they enter a less dense material?
bends away from the normal
Usually, the higher the density of a material the slower the wave speed
an exception to this is sound waves which travel faster in denser mediums
What happens if the wave slows down after crossing the boundary?
it bends towards the normal
What happens if the wave speeds up once crossing the boundary?
it bends away from the normal
What happens to the wavelength and frequency of a wave when its refracted?
.wavelength changes
.frequency stays the same
What happens to the wavelength if the wave enters a denser medium?
it decreases
What happens when the wave is travelling along the normal?
It changes speed but isn’t refracted
if the wave bends towards the normal then the angle of refraction is smaller
if a wave bends away from the normal the angle of refraction is bigger
What is the optical density of a material?
a measure of how quickly light can travel through it - the higher the optical density, the higher the light waves travel through it
if the 2nd material is optically denser then the refracted ray bends towards the normal - the angle of refraction is smaller than the angle of incidence
if the 2nd material is less optically dense then the refracted ray bends away from the normal - the angle of refraction is bigger than the angle of incidence
Refraction can cause optical illusions
because the light waves appear to come from a different position to their actual source.
