light – reflection & mirrors 1.when light hits an object – a.the light can be reflected....

Light – Reflection & Mirrors1. When light hits an object –

a. The light can be reflected.

b. The light can be absorbed (opaque).

c. The light can be transmitted (transparent or translucent).

2. Kinds of Reflection – Regular reflection occurs when parallel rays of light hit a smooth surface.

Light – Reflection & Mirrors3. Diffuse Reflection –occurs when parallel rays

of light hit a bumpy or uneven surface. Most objects reflect light diffusely!

Light – Reflection & Mirrors4. Plane Mirrors – Flat mirrors produce an image

that is right – side up and the same size as the object being reflected called a virtual image.

5. Virtual Images vs. Real Images –

Right-Side Up Upside Down

or or

Upright Inverted

Light – Reflection & Mirrors

6. Concave Mirrors – Can form either virtual images or real images.

Light – Reflection & Mirrors7. Convex Mirrors – Always form virtual images.

Refraction and Lenses8. Refraction of Light – When light rays enter a

new medium at an angle, the change in speed causes the light rays to bend or change direction.

9. Index of Refraction – How much a material causes a light ray to bend when the light ray enters that material.

10.Prisms, Rainbows, & Mirages – all are examples of light being refracted.

Refraction and Lenses11.Concave Lenses - In this picture the concave

lens forms an image that is smaller, upright and just in front of the actual object.

Refraction and Lenses12. Convex Lenses – can produce both virtual and real

images.

Color13.Color – The color of an object is the Color of

the light it reflects.

14.Objects and White Light – Objects that appear white reflect all the colors of the visible light spectrum. Objects that appear black absorb all the colors of the visible light spectrum.

15.Primary Colors of White Light– Red, Green, and Blue can be combined to form secondary colors. Red + Green = Yellow Pg. 584 in Text

Color

16.Complementary Colors of White Light – Any two colors that combine to form white light.

Ex. Yellow + Blue = White

17.Pigments – Substances that are used to color other materials. The more pigments that are combined the darker the mixture looks.

The Human Eye18. Nearsightedness - The eyeball is too long.

19.Farsightedness – The eyeball is too short.

Both can be corrected by eye glasses or contacts.

Using light

20. Telescopes – use lenses or mirrors to collect and focus light.

21. Microscopes – use a combination of lenses to produce and magnify an image.

22. Cameras – use lenses to focus light and record an image of an object.

Using light23. Laser – Light Amplification Stimulated Emission

Radiation

Laser Beam – waves of the same wavelength or color and all the waves are in sync or in step with each other.

24. Uses of Lasers –

a. To make compact discs [CD’s]

b. Surgery – Soft Tissue

c. Holograms –> 3 –Dimensional photographs by using the light from a laser.

Using light25. Optical Fibers – Long, thin strands of glass or plastic

that can carry light for long distances without allowing the light to fade out .

Total Internal Reflection – Light keeps going even if the optical fiber is curved or curled up .

Using light26. Communications – Greatly improved by fiber

optics: a. Telephone Service

b. Computer Networks

c. Cable T.V. Systems

27. Medicine – Optical Fibers can be used to examine internal organs without major surgery.