Waves have three main properties, or characteristics.
- Amplitude: Amplitude is the distance from the resting point or equilibrium of a wave, to its crest. Amplitude measures how much a wave is displaced from its equilibrium. More energetic waves have larger amplitudes. Think of waves in an ocean: Waves that carry more energy are taller and are farther displaced from the regular waterline, so they have larger amplitudes.
- Wavelength: Wavelength is measured from a point on one wave to the same point on the next wave (trough to trough, or crest to crest). The difference between colors is caused by different wavelengths of light. Red has a longer wavelength than blue.
- Frequency: Frequency is the number of waves that pass a point in a given unit of time. It is measured in hertz (Hz), which is the number of waves per second. Frequency and wavelength are inversely proportional if the waves are traveling the same speed, meaning: When frequency is higher, wavelength must be smaller. When frequency is lower, wavelength must be longer.