Chapter 9: Waves and Light. 9.1: Waves of the E lectromagnetic Spectrum. As you sit and read your book, you are surrounded by waves from the sun that you cannot see or hear. These are electromagnetic waves
Chapter 9: Waves and Light
An electromagnetic wave is made up of vibrating electric and magnetic fields that move through space or some medium at the speed of light
The energy that the electromagnetic wave transfers through matter or space is called electromagnetic radiation
Regular reflection occurs when parallel rays of light hit a smooth surface
All light rays reflect at the same angle
This will permit you to see a clear image
Diffuse reflection occurs when parallel rays of light hit an uneven surface.
Each light ray hits the surface at different angles because the surface is uneven
This causes the image to be blurry or not seen
Plane Mirror: flat sheet of glass
This type of mirror produces a virtual image. So it’s an image that doesn’t exist.
Your image appears to be behind the mirror
The virtual image is upright and the same size of the object
Have you ever looked at yourself in curved mirrors at a fun house?
If the object is farther away from the mirror than the focal point, the reflected rays forms a real image
A real image can be projected on a piece of paper, and can be larger or smaller than the object they are also upside down
If an object is between the mirror and the focal point, the reflected rays form a virtual image
Convex mirrors curve outwards
A convex mirror produces a virtual image that is always smaller than the object
When light hits an object, it can be reflected, refracted and /or absorbed
Optical Illusion In a Fish Tank
There is only one fish in
the tank, but refraction
makes it look
as though there are two.
Refraction of Light
The light ray bends
as it passes through different mediums.
When white light enters s prism, each wavelength is refracted by different amount
The longer the wavelength and less the wave is bent.
Water + Light= Rainbow
When you look through binoculars, a camera or eyeglasses you are using lens to bend light
A lens is a curved piece of glass or other transparent material that refracts light
The type of image formed by a lens depends on the shape of the lens and the position of the object
A concave lens produces a virtual image that is upright and smaller than the object
How a Convex Lens Works
The type of image formed by a convex lens depends on the object’s position.
The Changing Speed of Sound
Sound travels faster through steel than air, even though steel is denser, because steel is also less compressible