1wave
A disturbance that transfers energy from place to place
2mechanical wave
A wave that requires a medium through which to travel
3electromagnetic waves
A form of energy that can move through the vacuum of space.
4transverse wave
A wave that moves the medium in a direction perpendicular to the direction in which the wave travels
5compressional wave
matter in the medium moves back and forth along the same direction that the wave travels
6amplitude
the height of a wave's crest
7wavelength
Horizontal distance between the crests or between the troughs of two adjacent waves
8frequency
the number of complete wavelengths that pass a point in a given time
9wave speed
frequency x wavelength
10reflection
The bouncing back of a wave when it hits a surface through which it cannot pass.
11refraction
The bending of a wave as it passes at an angle from one medium to another
12diffraction
The bending of a wave as it moves around an obstacle or passes through a narrow opening
13interference
the combination of two or more waves that results in a single wave
14period
the time it takes one wavelength to pass a given point
15crest
Highest point of a wave
16trough
Lowest point of a wave
17rarefaction
a part in a longitudinal wave where the particles are spread apart
18compression
The part of a longitudinal wave where the particles of the medium are close together.
19Loudness
a sound's intensity (amplitude)
20Decibel
a unit that compares the intensities of different sounds
21Pitch
a tone's experienced highness or lowness; depends on frequency
22Echo
a reflected sound wave
23Doppler effect
A change in sound frequency caused by motion of the sound source, motion of the listener, or both.
24Electromagnetic radiation
a kind of radiation including visible light, radio waves, gamma rays, and X-rays, in which electric and magnetic fields vary simultaneously.
25Gamma rays
Electromagnetic waves with the shortest wavelengths and highest frequencies
26X-rays
Electromagnetic radiation having a very short wavelength; can penetrate substances such as skin and muscle.
27Ultraviolet light
part of the electromagnetic spectrum that consists of waves with frequencies higher than those of visible light and lower than those of x-rays
28Visible light
Electromagnetic radiation that can be seen with the unaided eye
29Infrared light
Infrared light has longer wavelengths, penetrates more deeply, has less energy, and produces more heat than visible light; makes up 60 percent of natural sunlight.
30Microwaves
Electromagnetic waves that have shorter wavelengths and higher frequencies than radio waves.
31Radio waves
Electromagnetic waves with the longest wavelengths and lowest frequencies
32Focal length
the distance from the center of a lens to the focal point
33Convex lens
A lens that is thicker in the middle than at the edges
34Concave lens
A lens that is thinner in the center than at the edges
35Pigment
A colored chemical compound that absorbs light, producing color.
36Light ray
narrow beam of light traveling in a straight line
37Medium
matter through which a wave travels
38Law of reflection
the angle of incidence is equal to the angle of reflection
39Focal point
the point at which rays parallel to the optical axis reflect and meet