1. Concave Mirrors
SNC2D1
Mr. Findlay

2. Why do we see things?
Light that reflects off object enters our eyes!

3. Virtual vs Real Images
A virtual image is an image formed by rays that appear to be coming from a certain location (i.e. behind the mirror), but actually are not. These images cannot be seen on a screen.
A real image is an image formed by rays that converge (meet) at a certain location. These images can be seen on a screen.

4. What is a Concave Mirror?
A mirror that has a reflective surface that curves inwards. (i.e. “caves in”)

5. Mirror Terminology C – F – f – V – PA – Centre of Curvature Focus
Focal length PA
Vertex f
Principal Axis
(through C & V)

6. How do light rays reflect?
Light rays that go in along the PA...
Reflect back on themselves

7. How do light rays reflect?
Light rays that travel parallel to the PA...
Reflect through the focus.

8. How do light rays reflect?
Light rays that travel through the centre...
Reflect back through the centre.

9. How do light rays reflect?
Light rays that travel through the focus...
Reflect parallel to the PA.

10. How can we use these rays to help us find the image?
Three (and a half) steps:
Draw a ray coming in parallel to the PA and draw its reflection.
Draw a ray coming in through the focus and draw its reflection.
Draw a ray coming in through the centre and draw its reflection.
Half: Where the three ________ rays converge, the image is there!
reflected

11. Example

12. Practice

13. Practice