Concave and Convex Mirrors

1. Concave and Convex Mirrors Section 4.4 Lesson 10

2. Convex mirror • This mirror bulges outwards from its centre • It would be like putting a mirror on the outside of a ball! • One of the main differences between concave and convex is that the focal point for a convex mirror is behind the mirror instead of in front of it.

3. Uses of convex mirrors

4. Finding the focal point using convex mirrors The reflected rays can be extended into virtual space where they will meet at the focus – what does that mean for all images seen in a convex mirror? Aim some incident rays at a convex mirror… F They will all be virtual images! When the rays are aimed at the convex reflective surface they reflect outwards and diverge. Think about where these rays could meet…

5. C F F C Ray Diagrams for Convex Mirrors Step 1 – Draw in a line through the vertex. A ray travelling parallel to the principal axis will reflect as if coming from the focal point. Remember to use a dotted line for rays that extend into virtual space.

6. C F F C Ray Diagrams for Convex Mirrors Step 2 - A ray travelling as though it is going through the focal point will reflect back parallel to the principal axis.

7. C F F C Ray Diagrams for Convex Mirrors Step 2 - A ray travelling as though it is going through the focal point will reflect back parallel to the principal axis. Draw in the reflected ray first then extend it into virtual space parallel to the principal axis

8. Ray Diagrams for Convex Mirrors C F F C Step 3 - A ray travelling as though it is going through the centre will reflect back on itself. Note that a third ray is not really needed to locate the image

9. C F F C Ray Diagrams for Convex Mirrors Back to step 2… upright virtual smaller closer L: __________ O: _____________ S: ____________ T: ________

10. Notes • Complete the handout • 4.4 Convex Mirrors: Drawing Ray Diagrams to Locate Images