1. The moons of the planet Neptune move in circular paths around the planet. They continuously accelerate towards the centre of Neptune. The acceleration changes the.................................................. of each moon but does not change its................................................... The force causing the acceleration is a.................................................. force.

2. Reflection and Refraction L.O.:  What can say about the reflection of a light ray by a plane mirror?  What is refraction? previous HW: 104-107 and worksheets) Tomorrow: bring a ruler

3. Reflection Reflection

4. Reflection

5. Reflection

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

7. 6-Feb-16 Location of image The image formed by a plane (flat) mirror is: the same distance behind the mirror as the object is in front of it.

8. PLANE MIRROR: UPRIGHT, SAME SIZE, VIRTUAL

9. The image seen in a mirror is a virtual image. The light rays appear to come from the image. A virtual image cannot be projected onto a screen.

10. Real images:  Can be projected onto screens.  They are produced by focusing light rays onto a screen.

11. Refraction What happens when light crosses an interface ( a boundary between two transparent media) ?

12. Refraction Refraction

13. Refraction

14. Refraction

15. But, if light meets a boundary between two transparent materials at an angle of 90 o (i.e along the normal) then, there is NO change in direction.

16. Workbook page 110, questions: 1a-b & 3.

17. Starter: When a wave crosses the boundary between one medium and another the wave _____- changes. If light travels across the boundary into a ___ dense material, the light slows down and the wavelength decreases. The ______ doesn’t change. If light strikes the surface along the _____, it will not change directions. Clues: Frequency: it depends on the source Speed: depends on the medium

18. Starter: When a wave crosses the boundary between one medium and another the wave _____- changes. If light travels across the boundary into a ____ dense material, the light slows down and the wavelength decreases. The ___________doesn’t change. If light strikes the surface along the ________, it will not change directions. Clues: Frequency: it depends on the source Speed: depends on the medium speed more frequency normal