Transcript Date Lesson 3: Refraction Lesson Outcomes Task 1: Explain that light is refracted towards the normal as it enters a denser transparent material and away when it leaves.

Date
Lesson 3: Refraction
Lesson Outcomes
Task 1:
Explain that light is refracted
towards the normal as it
enters a denser transparent
material and away when it
leaves . Level 5
Task 2:
Draw a ray diagram to
describe what happens when
a ray of light is refracted on
entering and leaving a glass
block. Level 6
Task 3:
Apply knowledge of refraction
to everyday examples. Level
How I did
Targets
Connector:
(Level 4)
Explain that
light bending at
the surface of
glass or water
can deceive us
Look at the set
up of a straw in
a beaker, draw
what you see
BIG picture
• What skills will you be developing this
lesson?
•
•
•
•
•
•
•
•
•
ICT
Numeracy
Literacy
Team work
Self management
Creative thinking
Independent enquiry
Participation
Reflection
HOW SCIENCE WORKS
• How is this lesson relevant to every day
life? (WRL/CIT)
Bending light
The speed of light waves depends on the material they
are travelling through.
air = fastest
glass = slower
diamond = slowest
If light waves enter a different material (e.g. travel from
glass into air) the speed changes.
This causes the light to bend or refract.
air
glass
New Information for Task 1
Task 1 (Level 5)
• Task 1:
Keywords for Task 1:
• angle of incidence
•Angle of refraction
• Normal
•
• Task 1:
• Label diagram using key words
• Explain why light gets refracted
•
•
Task 1: Answers
Light gets refracted
as it slows down, light
travels fastest
through air, and
slower through glass.
The change is speed
causes the light to
bend.
Task 1: Review
Go back to your lesson outcome grid and fill out
the ‘How I did’ and the ‘Targets’ column.
Lesson Outcomes
Task 1:
Level 5
How I did
Met?
Partly met?
Not met?
Targets
How can I improve
on task 1?
New Information for Task 2
incident
light ray
normal
semi-circular glass
block
refracted
light ray
angle measured
here
Task 2 (Level 6)
•
•
•
•
•
•
Carefully mark the angles on the
sheet of paper, making sure that
they are lined up with the centre of
the flat side of the glass block.
Shine the light accurately along the
first line so that the light ray hits
the centre of the glass block.
Mark the line of light that comes
out of the curved side of the glass
block accurately, using a ruler,
Measure the angle between the
straight through line and each light
ray.
Record results
Draw a grph
Keywords for Task 2:
• refraction
•Light
•Bends
•Angle
•ray
Task 2: Answers
Angle of incidenceº
Angle of refractionº
Task 2: Review
Go back to your lesson outcome grid and fill out
the ‘How I did’ and the ‘Targets’ column.
Lesson Outcomes
Task 2:
Level 6
How I did
Met?
Partly met?
Not met?
Targets
How can I improve
on task 2?
New Information for Task 3
Task 3
•
•
•
•
•
•
•
•
•
Cut a piece of graph paper in two.
2
Put one of the pieces of graph paper under an empty beaker.
3
Place the second piece of graph paper next to the beaker.
4
Look from above. You will notice that the squares on the graph
paper look about the same size as each other.
5
Now half fill the beaker with water and look again.
6
Draw what you see. Pay particular attention to the size of the
squares on the two pieces of graph paper.
7
Now slowly lift the piece of graph paper that is next to the
beaker until the sizes of the squares look the same (you need to
keep this piece of graph paper next to the beaker).
8
Measure the depth of the water and the distance from the
surface of the water to the lifted piece of graph paper.
9
Try steps 5–8 again with the beaker full of water.
Task 3: (Level 7)
• Task 3:
• Use the data to explain which
material caused the most
refraction
• Task 3: Extension
Keywords for Task 3:
• refraction
• incidence
• angle
Task 3: Answers
Task 3: Review
Go back to your lesson outcome grid and fill out
the ‘How I did’ and the ‘Targets’ column.
Lesson Outcomes
Task 3:
Level 7
How I did
Met?
Partly met?
Not met?
Targets
How can I improve
on task 3?
Homework
• Homework task:
• Due date:
• Criteria for level 5:
• Criteria for level 6:
• Criteria for level 7:
Review of lesson
•
•
•
•
•
•
•
This is the answer what was the question?
Incidence
Refraction
Ray
Light
Glass
diamond