1. Law of Reflection: equal angles
1. PLANE (FLAT) MIRROR
ACTUAL light path
APPARENT light path
normal
Law of Reflection: equal angles
VIEWER
OBJECT
IMAGE:
same size,
equal distance behind

2. Look at the demonstration set up on the front.
Title: Refraction June 2018
Starter
Look at the demonstration set up on the front.
Can you explain it?

3. Title: Refraction 12 June 2018
Today we will be finding out about refraction.
You will know you have been successful when you have:
Defined refraction by describing an example of when it occurs. (Level 5)
Independently carried out a practical to investigate how light travels through different substances (Level 6)
Used ideas about refraction to describe some real-life situations where refraction occurs (Level 7/8)

4. Refraction Perspex block Angle of Refraction Angle of Incidence
Incident ray
Normal Line

5. Aim: To Investigate what happens when you shine a light through a perspex block
Normal Line
Incident ray
Perspex block

6. Diagram – Of set up of equipment
Title – Refraction
Aim- Investigate the relationship between angle of incidence and angle of refraction
Diagram – Of set up of equipment
Table of results (at least 6 sets of results between 2)
Angle of incidence / º
Angle of refraction / º

7. Graphs – Remember! The dependent variable goes on the x-axis
Marks on graphs are awarded for
Meaningful title
Correctly labelled axes
A suitable scale
Your graph being big enough
Points correctly plotted in pencil
A suitable line of best fit

8. Now plot a graph of your results
Angle of refraction /°
Angle of incidence/°

10. NB The graph is NOT straight

11. Conclusion
What shape is the graph?
What does this mean?
What is the relationship between the
angle of incidence and the angle of
refraction?
What problems did you have?

12. Refraction
Is the bending of light when a ray changes speed. If it is made to slow down it will bend towards the normal line.

13. Refraction

14. Refraction
Explain why the man sees the fish in a position closer to the surface than it actually is. Extension: How do you think he learns to overcome this?

15. Refraction

16. Refraction changes apparent depth
Have you ever noticed how a shallow pond can look even shallower than it actually is? This is because the path of the ray has changed. Because light travels in a straight line we judge the distance incorrectly.

17. Homework
Reflection and Refraction banding exercise.

18. Homework Learn spellings:
Reflection, Refraction, Lens, Dispersion, Electromagnetic, spectrum, incidence,
Learn ray diagrams & labels for reflection in a plane mirror & refraction in a glass block.