Glossary
Amplitude
The maximum displacement or distance moved by a point on a vibrating body or wave measured from its equilibrium position.
Example:
A loud sound wave has a large amplitude, while a quiet sound wave has a small one.
Antinode
A point along a standing wave where the wave has maximum amplitude, meaning the greatest displacement.
Example:
On a vibrating jump rope, the point where the rope swings highest and lowest is an antinode.
Frequency (f)
The number of complete cycles or oscillations of a wave that pass a given point per unit of time.
Example:
If a wave completes 5 cycles in 1 second, its frequency is 5 Hertz (Hz).
Interference
The phenomenon that occurs when two or more waves superpose to form a resultant wave of greater, lower, or the same amplitude.
Example:
When two speakers play the same note, you might notice spots where the sound is louder or quieter due to constructive or destructive interference.
Mechanical Waves
Waves that require a medium to propagate, meaning they cannot travel through a vacuum.
Example:
The vibrations traveling through a guitar string when plucked are an example of a mechanical wave.
Node
A point along a standing wave where the wave has minimum amplitude, meaning there is no displacement.
Example:
If you pluck a guitar string, the fixed ends of the string are always nodes because they cannot move.
Period (T)
The time it takes for one complete cycle or oscillation of a wave to pass a given point.
Example:
If a pendulum swings back and forth once every 2 seconds, its period is 2 seconds.
Sound Waves
Longitudinal mechanical waves that result from vibrations and travel through a medium, such as air, water, or solids.
Example:
When a speaker plays music, it creates sound waves that travel through the air to your ears, allowing you to hear the melody.
Velocity (v)
The speed at which a wave travels through a medium, determined by its frequency and wavelength.
Example:
Light waves travel at an incredibly high velocity in a vacuum, approximately 3 x 10^8 m/s.
Wavelength (λ)
The spatial period of a wave, the distance over which the wave's shape repeats.
Example:
In a ripple tank, the distance between two consecutive crests of a water wave is its wavelength.
Waves
Disturbances that transfer energy and momentum from one location to another without the permanent transfer of mass.
Example:
When you drop a pebble into a pond, the ripples that spread outwards are waves transferring energy across the water's surface.