# wave amplitude

## energy and amplitude

A wave caused by a disturbance with more energy has greater amplitude. Imagine dropping a small pebble into a pond of still water. Tiny ripples will move out from the disturbance in concentric circles. The ripples are low- amplitude waves with very little energy. Now imagine throwing a big boulder into the pond. Very large waves will be generated by the disturbance. These waves are high-amplitude waves and have a great deal of energy.

## what is wave amplitude

Wave amplitude is the maximum distance the particles of the medium move from their resting positions when a wave passes through. The resting position of a particle of the medium is where the particle would be in the absence of a wave. The Figure 1.1 show the amplitudes of two different types of waves: transverse and longitudinal waves. In a transverse wave, particles of the medium move up and down at right angles to the direction of the wave. Wave amplitude of a transverse wave is the difference in height between the crest and the resting position. The crest is the highest point particles of the medium reach. The higher the crests are, the greater the amplitude of the wave. In a longitudinal wave, particles of the medium move back and forth in the same direction as the wave. Wave amplitude of a longitudinal wave is the distance between particles of the medium where it is compressed by the wave. The closer together the particles are, the greater the amplitude of the wave. Q: What do you think determines a waves amplitude? A: Wave amplitude is determined by the energy of the disturbance that causes the wave.

## whats the matter

Waves that travel through mattersuch as the fabric of a flagare called mechanical waves. The matter they travel through is called the medium. When the energy of a wave passes through the medium, particles of the medium move. The more energy the wave has, the farther the particles of the medium move. The distance the particles move is measured by the waves amplitude.

## instructional diagrams

No diagram descriptions associated with this lesson

## questions

all waves that travel through matter are called

``````a) longitudinal waves.

-->  b) mechanical waves.

c) transverse waves.

d) surface waves.
``````

the matter a wave travels through is called the material of the wave.

``````a. true

-->  b. false
``````

the more energy a wave has, the farther the particles of matter move.

``````-->  a. true

b. false
``````

the position of a particle of matter in the absence of a wave is called the

``````a) trough.

b) midline.

-->  c) resting position.

d) normal location.
``````

a wave with greater energy has a larger amplitude.

``````-->  a. true

b. false
``````

in all mechanical waves, particles of the medium move up and down when the wave passes through them.

``````a. true

-->  b. false
``````

## diagram questions

No diagram questions associated with this lesson