1. While you are watching the video think about why this is happening.

2. Mirrors & Lenses Notes

3. Light Rays & the Path of Light
If you could trace the path of one light wave when it leaves its source you would find that light travels in straight lines.
Use an arrow called a ray to show the path and direction of a light wave.

4. Rays & Reflected and Refracted Light
Rays help to show the path of light even after it bounces or bends.
Light waves that bounce off objects are reflected.
Light waves that bend when passing from one medium to another are refracted.
Rays in ray diagrams can show changes in the direction of light due to reflection & refraction.

5. Ray Diagram Vocabulary
Optical (Principle) axis – A straight line drawn outward from the center of the mirror or lens.
Focal point – The point at which rays meet after reflection or refraction.
Focal length – The distance between the surface of the mirror or lens and the focal point.

6. Mirrors & Reflection of Light
The shape of a mirror affects the way light reflects from it.
Mirrors are classified by shape. There are 3 different shapes of mirrors:
Plane
Concave
Convex

7. Plane Mirrors A plane mirror is a mirror that has a flat surface.
In a plane mirror the image is right-side up and the same size as the object.
Images in plane mirrors are reversed from left to right.
In a plane mirror the image appears to be the same distance behind the mirror as the object is in front of the mirror.
So the image formed is a virtual image.
A virtual image is an image through which the light does not travel.

8. Concave Mirrors
A concave mirror is a mirror that is curved inward like the inside of a spoon.
If the object is more than 1 focal length away from the mirror, the image is up-side down and smaller in size than the object.
If the object is more than 1 focal length away from the mirror, the image appears to be in front of the mirror.
So the image formed is a real image.
A real image is an image through which the light passes.

9. Concave Mirrors
If the object is less than 1 focal length away from the mirror, the image is right side up and larger in size than the object.
If the object is less than 1 focal length away from the mirror, the image appears to be behind the mirror.
So the image formed is a virtual image.

10. Convex Mirrors
A convex mirror is a mirror that is curved outward like the back of a spoon.
In a convex mirror the image is right-side up and smaller in size than the object.
In a convex mirror the image appears to be behind the mirror.
So the image formed is a virtual image.

11. Why is the girl’s reflection in the spoons different
Why is the girl’s reflection in the spoons different? Which picture shows the back of the spoon?

12. Lenses & Refraction of Light
A lens is a transparent object that forms an image by refracting light.
The shape of a lens affects the way light refracts from it.
Lens are classified by shape.
There are 2 different shapes of lenses:
Concave – This lens causes rays to converge (come together)
Convex – This lens causes rays to diverge (spread apart)

13. Convex Lenses
A convex lens is a lens that is thicker in the middle than at the edges.
If the object is less than 1 focal length away from the lens, the image will be a right-side up, larger, virtual image.
If the object is more than 2 focal lengths away from the lens, the image will be a up-side down, smaller, real image.
Convex lenses are used in magnifying glasses, cameras, and sometimes eyeglasses.

14. Concave Lenses
A concave lens is a lens that is thinner in the middle than at the edges.
Concave lenses form images that are right-side up and smaller than the original object.
Because the rays diverge and never touch the images are all virtual images.
Concave lenses are used in telescopes, microscopes, and eyeglasses.