Refraction and reflection Flashcards
What is the incident ray
The incoming light ray onto the mirror
What is the reflected ray
The light ray that is reflected from the mirror
What is the normal
The line perpendicular to the mirrors surface, at the point where the light ray is reflected
Angle of incidence and angle of reflection
theta/θ i and theta/θ r
when does reflection occur
Reflection occurs when light, sound, or other waves encounter a boundary and bounce back.
What is a refraction
Often when a wave travels from 1 medium to another, it will speed up or slow down. This can cause refraction. Eg. when a wave crosses a boundary between 2 different media such as air to water, it can change direction
What is the refractive index
a measure of how much the speed of light changes when it passes through that substance compared to its speed in a vacuum.
If a wave speeds up when it goes into a new median which way will it bend to
it bends away from the normal ray
If a wave slows down when it goes into a new median which way will it bend to
it bends towards the normal ray
practical of angle of incidence angle of refraction and refractive index
method[4]
graph interpretation[2]
method:
trace
mark positions from incident ray and emergent rays
measure angle i and r
repeat at different angles of incidence
graph interpretation:
plot i on y axis r on x axis
gradient = refractive index (mention: sin(i)/sin(r) = n (refractive index))
Snell’s law
n=c/v
c= speed of light in vacuum
v=speed of light in medium
refractive index equation
n= sinθi/sinθr
total internal reflection equation
sin c(critical angle) = 1/n
