AQUINAS DIOCESAN GRAMMAR Refraction of Light. AQUINAS DIOCESAN GRAMMAR The bending of light is...
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Transcript of AQUINAS DIOCESAN GRAMMAR Refraction of Light. AQUINAS DIOCESAN GRAMMAR The bending of light is...
AQUINAS DIOCESAN GRAMMAR
Refraction of Light
AQUINAS DIOCESAN GRAMMAR
The bending of light is called refraction.
Refraction happens when light travels from one material (e.g. air) into a different material (e.g. glass or water).
AQUINAS DIOCESAN GRAMMAR
Incident ray
normal
refracted ray
normal
Glass block
Air
i
r
i = angle of incident
r = angle of refraction
AQUINAS DIOCESAN GRAMMAR
Light travels more slowly in glass than in air
In air (and a vacuum) light travels at 300,000,000 m/s (3 x 108 m/s), in glass its speed falls to 200,000,000 m/s (2 x 108 m/s).
Light is refracted because its speed changes when it enters another medium.
Demo
AQUINAS DIOCESAN GRAMMAR
The angle between the ray entering the block and the normal is called the angle of incidence (i).
The angle between the ray inside the block and the normal is called the angle of refraction (r).
normal
Glass block
Air
i
r
AQUINAS DIOCESAN GRAMMAR
Laws of Refraction
When a ray of light passes from an optically less dense medium to an optically more dense medium, at an angle, the ray is refracted towards the normal.
normal
Glass block
Air
i
r
normal
Glass block
Air
When a ray of light passes from an optically more dense medium to an optically less dense medium, at an angle, the ray is refracted away from the normal.
AQUINAS DIOCESAN GRAMMAR
What do you think will happen to a ray of light striking an air-glass boundary at 90o?
Glass block
Air
AQUINAS DIOCESAN GRAMMAR
O
I
O
Real depth Apparent depth
AQUINAS DIOCESAN GRAMMAR
AQUINAS DIOCESAN GRAMMAR
AQUINAS DIOCESAN GRAMMAR
Red Richard
Orange of
Yellow York
Green Gave
Blue Battle
Indigo In
Violet Vain
AQUINAS DIOCESAN GRAMMAR
AQUINAS DIOCESAN GRAMMAR
The light enters your eye through the transparent cornea, passes through the lens and is focused on the retina.
The retina is sensitive to light and sends messages to your brain by way of the optic nerve.
The iris changes in size to vary the amount of light that enters through the pupil.