amplitude
Amplitude (noun) means In physics, the greatest distance a wave or vibrating object moves from its resting position, which for sound corresponds to loudness and for light to brightness. Example: “Doubling the amplitude of the sound wave makes the note much louder.”
How to Use Amplitude
Learner’s notesIn plain EnglishHow big a wave's swing is, from the middle to its highest point.
Standard scientific vocabulary; the 'extent' sense is literary and formal.
In everyday physics problems, remember the shorthand: amplitude is loudness, frequency is pitch.
Trace the full origin ↓Fill the Gap
Can you complete this real example?
Doubling the _____ of the sound wave makes the note much louder.
Etymology
From Latin amplitudo, from amplus 'large'.
Related Words
Rhymes for amplitude
See all rhymes for amplitude →Frequently Asked Questions
What is the difference between amplitude and frequency?
Amplitude measures how far a wave moves from its rest position, which for sound means how loud it is. Frequency measures how many wave cycles pass a point each second, which for sound means how high or low the pitch is. A wave can be loud and low, or quiet and high, because the two are independent.
What is the difference between amplitude and wavelength?
Amplitude is measured vertically, from the centre line of the wave to a peak, while wavelength is measured horizontally, from one peak to the next. Amplitude describes strength; wavelength describes size along the direction of travel.
How is amplitude measured?
It is measured in whatever unit describes the displacement of the thing that is oscillating: metres for a pendulum, pascals of pressure for sound, and volts for an electrical signal.