Amplitude is defined as what?

Amplitude is defined as what?

• A. The distance from crest to crest
• B. The distance from the middle level to the crest (or to the trough)
• C. The number of waves per second
• D. The speed of the wave

Answer: (B)

Amplitude measures how far a point on the wave moves from the rest position. For a transverse wave, this rest position is the middle level. The highest point is a crest and the lowest is a trough, so amplitude is the distance from the middle level to a crest (or to a trough). In other words, it’s half the distance between crest and trough. The distance from crest to crest would be the wavelength, not amplitude, and the other options describe frequency (how many waves per second) or speed (how fast the wave travels).

Amplitude measures how far a point on the wave moves from the rest position. For a transverse wave, this rest position is the middle level. The highest point is a crest and the lowest is a trough, so amplitude is the distance from the middle level to a crest (or to a trough). In other words, it’s half the distance between crest and trough. The distance from crest to crest would be the wavelength, not amplitude, and the other options describe frequency (how many waves per second) or speed (how fast the wave travels).