Properties of Waves and Frequency

Study Notes

Waves have several distinct properties that help describe their motion and energy, including frequency and wavelength.
Frequency is defined as how often something occurs, or how often a wave occurs.

The frequency of a wave is the number of waves that pass a point in a certain period of time.
Frequency can also be described as the number of waves that pass a point in one second.
Waves that are moving more quickly will have a higher frequency than waves that are moving slowly.

Wave frequency can be calculated using the frequency formula: Frequency = wave speed (v) / wavelength (λ)
Wavelength is the distance from the top of one wave to the top of the next wave, and its unit is meters.

Different types of waves have different frequencies.
Higher frequency waves have shorter wavelengths while lower frequency waves have longer wavelengths.
Frequency also corresponds to energy: high-frequency waves have higher energy, and low-frequency waves have low energy.

Visible light waves range from 430 trillion Hz waves (red light) to 750 trillion Hz waves (violet light).
The frequency of the light wave determines what color the human eye perceives.
Lower energy waves, with relatively lower frequencies, resulting in "warmer" colors such as red, orange, and yellow.
Higher frequency waves result in "cooler" colors such as green, blue, and violet.

Sound waves are lower energy mechanical waves and, therefore, have lower frequencies.
Sound waves range from 20 Hz to 20,000 Hz.
In sound waves, frequency is synonymous with pitch.
Lower frequencies result in lower-pitched sounds, while higher frequencies result in higher-pitched sounds.

The frequency and wavelength of a wave are inversely proportional, meaning when one increases, the other decreases.
The frequency and wavelength of waves determine the amount of energy the wave possesses.
Frequency and energy are directly proportional; when the frequency of a wave increases, so does the energy.
Very low-frequency waves make up sound and radio waves, which have relatively low energy.
Very high energy waves, such as x-rays and gamma rays, have very high frequencies.