1. Refraction through a glass block: Refraction through a glass block:
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Wave
slows down
and bends
towards
the normal due to
entering a
more dense
medium
Wave
speeds up
and bends
away from
the normal due to
entering a
less dense
medium

2. Refraction through a glass block: Refraction through a glass block:
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Wave slows down but is
not bent, due to entering
along the normal

3. Wave speeds up and bends away from the normal due to entering a
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Wave
speeds up
and bends
away from
the normal due to
entering a
less dense
medium
Wave
slows down
and bends
towards
the normal due to
entering a
more dense
medium

4. Refraction - at the air-glass boundary
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Refraction - at the air-glass boundary

5. Convex lens Focus Focal length Wave speeds up and bends away from
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Convex lens
Wave
speeds up
and bends
away from
the normal due to
entering a
less dense
medium
Focus
Focal length

6. Words – speed up, water, air, bent, medium
Refraction
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Refraction is when waves ____ __ or slow down due to travelling in a different _________. A medium is something that waves will travel through.
In this case the light rays are slowed down by the water and are _____, causing the ruler to look odd. The two mediums in this example are ______ and _______.
Words – speed up, water, air, bent, medium

7. Why does light change direction as it enters a material?
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In the muddy field the car slows down as there is more friction.
If it enters the field at an angle then the front tyres hit the mud at different times.
Tyre one hits the mud first and will move more slowly than tyre two.This causes the car to turn towards the normal.
Tyre Tyre2
Road
Mud

8. Refraction : Effects of Refraction
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This ruler appears bent because the light from one end of the ruler has been refracted,
but light from the other end has travelled in a straight line.
Would the ruler appear more or less bent if the water was replaced with glass?

9. The Archer fish
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The Archer fish is a predator that shoots jets of water at insects near the surface of the water, say on a leaf.
The fish does not aim at the refracted image it sees but at a location where it knows the prey to be.
image of prey
prey location

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15. Wave diagrams 1) Reflection 2) Refraction 3) Refraction 4) Diffraction
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1) Reflection
2) Refraction
3) Refraction
4) Diffraction

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