# Waves Vocabulary

## 28 terms

### wave

any disturbance that transmits energy through matter or empty space. For example there are water waves in the ocean and light waves from the sun

### wave energy

Energy can be carried away from its source by a wave.

### waves and work

As a wave travels, it does work on everything in its path. The waves do work on the water to make it move up and down.

### medium

substance through which a wave can travel. A medium can be a solid, a liquid, or a gas.

### electromagnetic waves

they do not need a medium although they can go through air, water and glass. Light is an electromagnetic wave that your eyes can see.

### mechanical waves

waves that require a medium

### transverse waves

Waves in which the particles vibrate in an up-and-down motion. It moves across or perpendicularly to, the direction that it is going.

### crest

highest point of a transverse wave.

### trough

the lowest point of a transverse wave

### longitudinal waves

(in a wave) when the particles of the medium vibrate back and forth along the path that the wave moves.

### compression

A part of a longitudinal wave where the particles are crowded together

### rarefaction

A part of a longitudinal wave where the particles are spread apart from each other.

### sound waves

A sound wave is an example of a longitudinal wave. sound waves travel by compressions and rarefactions of air particles.

### surface waves

When waves form at or near the boundary between two media, a transverse wave and a longitudinal wave can combine to form a surface wave.

### amplitude

the maximum distance that the particles of a medium vibrate from their rest position

### rest position

the particles of a medium stay when there are no disturbances

### wavelength

the distance between any two crests or two troughs or compressions next to each other in a wave

### frequency

The number of waves produced in a given amount of time. Expressed in Hertz (1 Hz=1/s)

### wave characteristics that equals more energy

larger amplitude=more energy
shorter wavelength=more energy
higher frequency=more energy

### wave speed

the speed at which wave travels
v = λ x f, wave speed = wavelength x frequency

### reflection

reflection happens when a wave bounces back after hitting a barrier. ex) an echo

### refraction

refraction is the bending of a wave as the wave passes from one medium to another at an angle. ex) prism

### diffraction

The bending of waves around a barrier or through an opening. ex) talking to the ticket box people

### interference

The result of two or more waves overlapping

### constructive interference

it is when the crests of one wave overlap the crests of another wave or waves
new wave=larger amplitude

### destructive interference

destructive interference happens when the crests of one wave and the troughs of another wave overlap.
new wave=smaller amplitude

### standing waves

The loops come from the interference between the wave you made and the reflected wave. It will look like as if its standing still.

### resonance

When an object vibrating at or near the resonant frequency of a second object causes the second object to vibrate