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Refraction: What is refraction?
When light is transmitted through a new material (or a substance), it
sometimes refracts. What does refraction mean?
Brief definition in your own words:
,R.efraction means the bending of light.
vv\-o_ci; etr,
auk
CtrReAre (...0 C in de siheS ccl-kfey-ert+bs-tan Les .
Draw how a pencil would look in this cup
of water. {The line in the middle of the
cup represents water.)
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Think of other substances or objects that light would refract when
traveling through. Where else have you seen refraction?
In the box below, draw and label your own example of when you might see light refracting.
Answers may vary. Examples include at the swimming pool when half of your body is
in the pool and the other half is out; when fishing, when wearing sunglasses and
looking out of the side of them, or glasses/contacts.
Refraction - Student Notes (Continued)
So, why do does light bend when it travels through different substances?
Light bends because it changes
when it moves
spe e
between materials that have different cies'--S
. Light
usually travels more ej ov\_:,i'
in more dense material.
4
When light travels from one
medium to a denser one
(ex. air to water), it will
bend -hcructrct the
normal.
Normal
Incident
Angle of
incidence
ray
When light travels from one
medium to a less dense one
(ex. oil to water), it will berIc
<yrn the
normai.
Rttfleci et.ti
ray
01
.-
Medium 1
(air)
hicelium 2
Angle of
refraction
(water)
The new angle is called the
G.
irar+i err\--
(R).
Re fratted
\ ray
When the angle of incidence (i) increases, the angle of refraction (R) also
increases. However, these two angles are NOT necessarily equal!
Refraction can also occur when light travels through air at different
temperatures.
air is less dense than 0/5t-)1 I ( r)ict
I
air. The bending of light through different air temperatures can cause a
The air close to the ground on a hot day is hotter
and less deYlse than the air higher up. The light from the sky directed at
the ground is bent upwards as it enters less dense air. This gives the illusion
of pools of water on the road, that aren't actually there!