What is happening here…??
Refraction
Success Criteria
Today you will:
Describe what happens when light is refracted
Record observations using a labelled diagram
Explain what happens when light travels through
a lens
Refraction
Refraction
Transparent objects can only be seen if light changes
direction when it passes through them.
This is refraction.
It happens because light travels at different speeds
in different materials, so one edge of a ray of light is
slowed down before the other.
How could we model refraction?
Refraction
Success Criteria
Today you will:
Describe what happens when light is refracted
Record observations using a labelled diagram
Explain what happens when light travels through
a lens
Investigating refraction
How does the refraction depend upon the angle of
the light arriving at the block?
Investigating refraction
Draw a line using a ruler, then draw the normal line
(remember this is always at a right angle)
Line up the side of the block with the first line and
set up the ray box to shine a ray of light towards it.
Draw dots to mark the light rays you can see.
Investigating refraction
1. The ray travelling into the glass
block is the incident ray. Label the
two incident rays on your diagram.
2. The ray travelling through the
glass block is the refracted ray.
Label the two refracted rays on
your diagram.
3. Describe the path of the light as
it travels towards and through the
block. Include light travelling along
the normal and at other angles.
Refraction
Success Criteria
Today you will:
Describe what happens when light is refracted
Record observations using a labelled diagram
Explain what happens when light travels through
a lens
Lenses
Where might you find a lens?
What do you think lenses do?
Refraction
Success Criteria
Today you will:
Describe what happens when light is refracted
Record observations using a labelled diagram
Explain what happens when light travels through
a lens
Uses of refraction – survival!
The Archer fish has to
overcome refraction just
to catch a meal…
https://www.youtube.com/watch?v=_6LsXA_FJIE
Uses of refraction – survival!
Where should spear-fishermen aim…
the head or the tail?