Wave Basics Flashcards
What happens when waves travel through a medium?
The particles of the medium vibrate and transfer energy and information between each other.
But overall, the particles stay in the same place.
What is the amplitude of a wave?
The displacement from the rest position to a crest or trough.
What is the wavelength?
The length of a full cycle of the wave (e.g. from crest to crest, or from compression to compression).
What is the frequency?
The number of complete cycles of the wave passing a certain point per second.
What is frequency measured in?
Hertz (Hz).
What does 1 Hz mean?
1 wave per second.
What is the period of a wave?
The number of seconds it takes for one full cycle.
What is the equation for the period of a wave?
Period = 1 ÷ Frequency
What happens in transverse waves?
The vibrations are perpendicular (at 90°) to the direction the wave travels (up and down).
What are examples of transverse waves?
- All electromagnetic waves e.g. light.
- S-waves.
- Ripples and waves in water.
What happens in longitudinal waves?
The vibrations are parallel to the direction the wave travels.
What are examples of longitudinal waves?
- Sound waves.
- P-waves.
What happens to the arrangement of particles in the medium longitudinal waves pass through?
Longitudinal waves squash up and stretch out the arrangement of particles in the medium they pass through, making compressions (high pressure, lots of particles) and rarefractions (low pressure, fewer particles).
What is the formula linking wave speed, distance and time?
v = x ÷ t
v = Wave speed (m/s) x = Distance (m) t = Time (s)
What is the formula linking wave speed, frequency and wavelength?
v = fλ
v = Wave speed (m/s) f = Frequency (Hz) λ = Wavelength (m)
