refraction Flashcards
what is refraction?
the bending of light rays as it passes from 1 medium to another
a light ray getting from point A to B, through 1 medium to another
Why does refracion occur?
the speed of light is different in different medums, and because of FERMSTS PRINCIPAL, light rays travel according to the fastest path, therefore it bends!
what is the speed of light in a vacuum?
3x10^8
what is fermats principal?
light follows a path that takes the least amount of time, therefore in 1 medium light travels in a straight line.
but in 2 it bends to travel a greater distance in the FASTER medium.
what is the refracted ray?
the ray that is “bent” after the incident ray
(EXTREMELY DIFFERENT from reflected ray, which is a ray that bounces off of a medium)
what is the angle of refraction?
the angle between the refracted ray and the normal
how is the angle of incidence and refraction measured?
relative to the normal AND NOT THE MATERIAL
how do you determine the direction of the refraction?
TOWARDS = less dense to more dense (ie: air to glass) angle of incidence is bigger than the angle or refraction
AWAY = more dense to less dense (ie: glass to air) the angle of incidence is smaller than the angle of refraction
MORE DENSE = higher index refraction because light is moving SLOWER
what is the index of refraction?
The index refraction is a number with no unit, that indicates HOW MUCH SLOWER (denser) a medium is than air in a vacuum (standard)
-> larger the index refraction, the more bent a light ray would be
what does it mean by dimensionless quantity?
refers to the index refraction having no unit, where units are “canceled out”
what is dispersion?
the seperation of whitelight into WAVELENGTHS/(COLOURS). due to the fact that each colour has a different index of refraction
what does optically density mean?
how slow the light rays move in that medium
