Physics – P5 Waves
5.1.1 Wave motion
Describing Wave Motion
Amplitude
Distance from the undisturbed position to the peak or trough of a wave.
Maximum or minimum displacement from the undisturbed position.
Symbol A, measured in metres (m).
Wavelength
The distance from one point on the wave to the same point on the next wave.
Transverse wave:
The wavelength – measured from peak to peak.
Longitudinal wave:
The wavelength – the centre of one compression to the centre of the next.
Symbol λ, measured in metres (m).
Frequency
The number of waves passing a point in a second.
Symbol f , measured in Hertz (Hz).
Time period
The time taken for a single wave to pass a point.
The time taken for one full cycle of wave.
Symbol T , measured in seconds (s).
When the x-axis is time:
5.1.2 Wave equation
1
,Physics – P5 Waves
Wave Equation
Wave speed
The distance travelled by a wave each second.
It’s the speed at which energy is transferred through a medium.
(Transverse and longitudinal waves have the same equation.)
Symbol ν, measured in metres per second (m/s).
v = wave speed in metres per second (m/s)
f = frequency in Hertz (Hz)
λ = wavelength in metres (m)
1 kHz = 1000 Hz (1kHz x 103)
5.1.3 Transverse and longitudinal waves
Waves
Waves – repeated vibrations transferring energy (not matter). Energy is
transferred by parts of the wave knocking nearby parts.
Transverse waves
The oscillations are perpendicular to the direction of energy transfer.
- Energy transfer is in the same direction as the wave motion.
- They transfer energy, but not the particles of the medium.
- Can move in a liquid or solid, not a gas.
- EM waves (transverse waves) can move in a vacuum.
Examples:
- Ripples on the surface of water
- S-waves (seismic waves)
- EM waves
- Light
- Vibrations of strings
Longitudinal waves
2
, Physics – P5 Waves
The oscillations are parallel to the direction of energy transfer.
- Energy transfer is in the same direction as the wave motion.
- They transfer energy, but not the particles of the medium.
- They can move in solids, liquids, and gases.
- They can’t move in a vacuum (since there are no particles)
Examples:
- Sound waves
- P-waves
Transverse waves VS Longitudinal waves
Transverse Longitudinal
3
5.1.1 Wave motion
Describing Wave Motion
Amplitude
Distance from the undisturbed position to the peak or trough of a wave.
Maximum or minimum displacement from the undisturbed position.
Symbol A, measured in metres (m).
Wavelength
The distance from one point on the wave to the same point on the next wave.
Transverse wave:
The wavelength – measured from peak to peak.
Longitudinal wave:
The wavelength – the centre of one compression to the centre of the next.
Symbol λ, measured in metres (m).
Frequency
The number of waves passing a point in a second.
Symbol f , measured in Hertz (Hz).
Time period
The time taken for a single wave to pass a point.
The time taken for one full cycle of wave.
Symbol T , measured in seconds (s).
When the x-axis is time:
5.1.2 Wave equation
1
,Physics – P5 Waves
Wave Equation
Wave speed
The distance travelled by a wave each second.
It’s the speed at which energy is transferred through a medium.
(Transverse and longitudinal waves have the same equation.)
Symbol ν, measured in metres per second (m/s).
v = wave speed in metres per second (m/s)
f = frequency in Hertz (Hz)
λ = wavelength in metres (m)
1 kHz = 1000 Hz (1kHz x 103)
5.1.3 Transverse and longitudinal waves
Waves
Waves – repeated vibrations transferring energy (not matter). Energy is
transferred by parts of the wave knocking nearby parts.
Transverse waves
The oscillations are perpendicular to the direction of energy transfer.
- Energy transfer is in the same direction as the wave motion.
- They transfer energy, but not the particles of the medium.
- Can move in a liquid or solid, not a gas.
- EM waves (transverse waves) can move in a vacuum.
Examples:
- Ripples on the surface of water
- S-waves (seismic waves)
- EM waves
- Light
- Vibrations of strings
Longitudinal waves
2
, Physics – P5 Waves
The oscillations are parallel to the direction of energy transfer.
- Energy transfer is in the same direction as the wave motion.
- They transfer energy, but not the particles of the medium.
- They can move in solids, liquids, and gases.
- They can’t move in a vacuum (since there are no particles)
Examples:
- Sound waves
- P-waves
Transverse waves VS Longitudinal waves
Transverse Longitudinal
3
