3 Electromagnetic Waves- transverse waves consisting of changing electric fields and changing magnetic fieldsElectric Field- a region of space exerts electric forces on charged particlesMagnetic Field- a region of space produces magnetic forces
4 If one changes the other changes so they regenerate each other Electromagnetic waves are produced when an electric charge vibrates or accelerates
5 Electromagnetic waves can travel though a vacuum, or empty space, as well as through matter!
6 Electromagnetic radiation- transfer of energy by electromagnetic waves traveling through matter or across space
8 Speed of LightAlbert Michelson ( )- American physicist who first measured the accurate speed of light.
9 All electromagnetic waves travel at 3.00x108 m/s
10 The only difference in electromagnetic waves is their wavelength and frequency Remember: v=λf
11 Wave or Particle?Electromagnetic radiation behaves sometimes like a wave and sometimes like a stream of particles.
12 Evidence for the Wave Model Thomas Young ( )- English physicist
13 Evidence for the Particle Model Albert Einstein ( )Proposed that light, and all electromagnetic radiation, consists of packets of energy called photonsPhotoelectric effect- emission of electrons from a metal caused by light striking the metal
18 Behavior of Light Light and Materials Materials can be transparent, translucent, or opaque
19 TransparentA material through which you can see clearly; transmits light, which means it allows most of the light that strikes it to pass through
20 TranslucentA material that scatters light; makes objects look fuzzy or unclear
21 OpaqueEither absorbs or reflects all of the light that strikes it; you cannot see through these objects
22 Interactions of LightWhen light strikes a new medium, the light can be reflected, absorbed, or transmitted.When light is transmitted, it can be reflected, polarized, or scattered
23 ReflectionImage- a copy of an object formed by reflected (or refracted) waves of lightRegular reflection- occurs when parallel light waves strike a surface and reflect all in the same direction (smooth polished surface)Diffuse reflection- when parallel light waves strike a rough, uneven surface, and reflect in many different directions
29 Separating White Light Into Colors White sunlight is made up of all the colors of the visible spectrumAs white light passes through a prism, shorter wavelengths refract more than longer wavelengths and the colors separateDispersion- process in which white light separates into colorsRed- longest wavelength- least bentViolet- shortest wavelength- bent most
31 The Colors of ObjectsThe color of any object depends on what the object is made of and on the color of light that strikes the object.Pigment- material that absorbs some color of light and reflects othersPhotography Link
32 Secondary Colors- Combination of 2 primary colors Primary Colors- 3 specific colors that can be combined in varying amounts to create all possible colorsIn Light: Red, Green, and BlueIn Pigment: Cyan, Magenta, and YellowSecondary Colors- Combination of 2 primary colorsIn Light: Cyan, Magenta, and YellowIn Pigment: Red, Green, and Blue
33 Complimentary ColorsIn Light: Any two colors that combine to make whiteIn Pigment: Any two colors that combine to make black
34 The Law of ReflectionRay diagram- shows how rays changed direction when they strike mirrors and pass through lenses.
36 Virtual image- a copy of an object formed at a location from which light rays appear to come Remember: rays do not actually come from behind the mirror!
37 Concave MirrorsConcave Mirrors- when the inside surface of a curved mirror is the reflecting surfaceFocal point- the point at which the light rays meetReal image- a copy of an object formed at the point where light rays actually meetCan be viewed on a surface such as a screenConcave mirrors can form either real or virtual imagesWhen the object is farther from the mirror than the focal point, the reflected rays meet in front of the mirrorWhen the object is closer to the mirror than the focal point the reflected rays spread out and appear to come from behind the mirror
39 Convex MirrorsConvex mirrors- when the outside surface of a curved mirror is the reflecting surfaceConvex mirrors always cause light rays to spread out and can only form virtual images
40 Lenses Light travels at 3.00 x 108 m/s in a vacuum. As it passes through new media it slows downAir- almost 3.00 x 108Water x 108Glass x 108
41 When light enters a new medium at an angle, the change in speed causes the light to bend or refract
42 Lens- Object made of transparent material that has one or two curved surfaces that can refract light Concave lens- curved inward at the center and is thickest at the outside edgesConcave lenses always cause light rays to spread out and can only form smaller virtual imagesConvex lens- curved outward at the center and is thinnest at the outer edgeConvex lenses form either real or virtual images