1. Prism What happens when we shine white light into a prism? White light Red lights bends the least Violet light bends the most Many colours blended together Copy please

2. Last lesson Refraction of light

3. Refraction Glass block Beam of light Light going from air to glass bends towards the normal Light going from glass to air bends away the normal

4. The mug trick!

6. Homework – To show and explain this to your parents! Due Friday 29 th Jan

7. Prism What happens when we shine white light into a prism? White light Red lights bends the least Violet light bends the most Many colours blended together

8. Today’s lesson Total Internal Reflection Fibre-optic cables Seeing colours

9. Another little investigation! Aim all beams at the centre of the semi circle

10. Another little investigation! Aim all beams at the centre of the semi circle

11. Total Internal Reflection

12. Critical Angle?

16. Critical angle

17. Total Internal Reflection If the angle is bigger than the critical angle we get total internal reflection Copy please!

18. Total Internal Reflection Critical angle sin c = 1/η sin(critical angle) = 1/(refractive index)

19. Examples of Total Internal Reflection

25. Seeing and colours

26. We see things because light is reflected into our eyes

27. Red objects only reflect red light

28. A Red objects in green light would look black (no reflected light)

29. Combining light YouTube - Bill Nye the Science Guy - 16 - Light and Color 1/3 YouTube - Bill Nye the Science Guy - 16: Light and Color 2/3Related Videos

30. Let’s try some questions! “Coloured lights”