A wave is

a disturbance of energy that travels through matter or space.

Examples of waves include

light, sound, x-rays, gamma radiation, radio, TV, ultraviolet radiation, etc.

Wave Parts

The highest peak of a wave is called the

crest.

The lowest peak of a wave is called the

trough. 

The trough to the crest is called the

amplitude. 

The total length of one wave is called the

wavelength. 

Frequency

Frequency measures the 

vibrations per second.

Frequency is measured in

hertz (Hz).

Human range of hearing is

50 Hz to 20,000 Hz.

Dogs range of hearing is 

20 Hz to 34,000 Hz.

Miscellaneous

When a light wave bounces off of  a mirror it is called

reflection.

The angle reflection into a mirror  

is equal to the angle leaving the barrier.

When a wave bends it is called

refraction.

The speed of sound through air is about 

331 meters per second (depending on the air temperature and density).

The speed of light is about

300 million meters per second.  Light could travels around the Earth about seven times in a second.

Constructive Interference Waves form when

 
two crests meet and combine their energy to make a bigger wave.  Like blowing on the book on the swing together.
 

Destructive Interference Waves form when

a crest of a wave meets the trough of another wave to form a smaller wave.

Sound

Volume is the 

intensity of the sound.  It has the same pitch, just louder or softer.

Pitch is the

“highness” or “lowness” of a sound;  like a violin versus a bass guitar.

Lenses

Light refracts/bends toward the

thicker part of a lens. 

Two common lenses are 

concave and convex.

A concave lens is thin at the

middle (Caves in).

A convex lens is thin at the 

edge(s). 
 

Color

The three primary pigments (paint) of color are

blue, magenta (red) and yellow. 

Mix them all together to get

black if you are lucky, but usually it’s brownish/grayish.

The three primary light colors are

blue, magenta (red) and green. 

Mix them all together to get

white light.

Other

The Pulphuric Effect, like the swinging golf ball, provides a

3d illusion because filtered light enters one eye about 10 milliseconds behind the other eye due to the filtered light. 

Persistence of Vision, like the wagon wheel spinning backwards, happens because an image

 stays in the brain for 1/20^th of a second.  Motion pictures take advantage of this by going at a speed of 1/24^th of a second.