# Sound and Light Vocabulary

## 17 terms

### Wave

a periodic disturbance in a solid, liquid, or gas as energy is transmitted through a medium

### medium

a substance through which a wave can travel, a physical environment in which phenomena occur

### Transverse wave

a wave in which the particles of the medium move perpendicularly to the direction the wave is traveling

### Longitudinal wave

a wave in which the particles of the medium vibrate parallel to the direction of wave motion

### Amplitude

the maximum distance the particles of a medium move away from their rest positions as a wave passes through the medium

### wavelength

The distance from any point on a wave to an identical point on the next wave

### wavespeed

the speed at which the wave travels; wavelength X frequency

### frequency

the number of complete wavelengths that pass a point in a given time (for example, per second)

### Reflection

the bouncing back of a ray of light, sound, or heat when the ray hits a surface that it does not go through

### Refraction

the bending of a wave caused by a change in its speed as it moves from one medium to another

### Diffraction

a change in the direction of a wave when the wave finds an obstacle or an edge, such as an opening

### Interference

the combination of two or more waves that results in a single wave

### Constructive Interference

Addition of two waves when the crest of one overlaps the crest of another, so that their individual effects add together. The result is a wave of increased amplitude.

### Destructive Interference

Addition of two waves when the crest of one overlaps the trough of another, so that their individual effects cancel each other. The result is a wave of decreased amplitude.

### Standing wave

A pattern of vibration that simulates a wave that is standing still

### Resonance

a phenomenon that occurs when two objects naturally vibrate at the same frequency

### Intensity

the amount of energy in a light or sound wave, which we perceive as brightness or loudness, as determined by the wave's amplitude