Waves ~ Properties

Waves ~ Properties

Transfer of Energy

• Just like wave particles, dominoes transfer energy from one to the next, without any one domino having to move the whole distance across the table.

• Motion of waves moves energy from one place to another.

• Waves are distinct from other energy transport systems because they can transport energy without the need to transport matter. 

Mechanical Waves vs Electromagnetic Waves

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  electromagnetic waves or light waves transfer energy, they travel through space and do not need a medium. 

• Mechanical waves transfer energy through a medium.

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transverse and longitudinal waves

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  transverse~ Seismic S Waves. Rope waves

• longitudinal waves~ Sounds Waves, spring waves

Characteristics of a Wave

• The highest point a wave reaches above equilibrium (midline) is its crest and the lowest point a wave reaches below equilibrium is its trough.

• Waves are measured by their amplitude, wavelength, and frequency.

• amplitude equals half the vertical distance from crest to trough. 

Sound Waves

• In sound waves, amplitude corresponds to loudness; as the wave amplitude increases, so does the loudness of the sound and the energy.

• The waves with the most amplitude are the loudest and have the most energy.

Wavelength

• Wavelength determines which waves we can sense.

• Humans can hear sound waves with wavelengths between about 0.02 m (high pitches) and 20 m (low pitches). 

Frequency

• Frequency is a measure of the number of times a wave cycles per unit of time (typically 1 second). 

• Frequency is also defined as the number of waves that pass a certain point in 1 second. Waves with higher frequencies have more energy.

Relationship

• The amount of energy transferred by waves in a given time is proportional to its frequency. This simply means that if a wave’s frequency doubles, the amount of energy being transferred by the wave doubles.

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To summarize:

• The amount of energy transferred by waves in a given time is proportional to the frequency.

• the energy of a wave is proportional to the square of the amplitude.

• in a sound wave, frequency determines pitch.

• in a sound wave, amplitude determines volume.