1. Today’s lesson
Critical angle
Total internal reflection
Dispersion

2. i
Ask them to set up the experiment as above. Gradually increase the angle of incidence. What happens?

3. i

4. Critical Angle?

5. i

6. Critical Angle i
Critical angle (when angle of refraction is 90º)

7. Critical Angle
90º
The Critical angle is the angle of incidence that produces an angle of refraction of 90º
Copy!
Critical angle

8. Total Internal Reflection
Bigger than Critical angle

9. Right-angled prisms
Demonstrate (or get them to do it) TIR in a right-angled prism.

10. Examples of Total Internal Reflection

11. Examples of Total Internal Reflection

12. Examples of Total Internal Reflection

13. Examples of Total Internal Reflection

14. Examples of Total Internal Reflection

15. Examples of Total Internal Reflection

16. Dispersion – Triangular prism

18. Dispersion – Triangular prism

19. Read pages 148 to 151
A suitable page(s) of their textbook

20. Questions! Page 149 Questions 1, 2 and 3.
Suitable questions from their textbook