wave
Travelling oscillating disturbance that carries energy without transfer of mass
[!abstract] wave pulse
Single disturbance, e.g. one jerk of a rope
[!abstract] periodic wave
Continuous stream of pulses
Properties
Wavelength
Distance between two successive identical pointsSym.
Amplitude
Maximum displacement of particlesSym.
Frequency
Number of peaks that pass through a point in one secondAnt.
period
Period
Time taken for one peak to pass through a pointAnt.
frequency
Speed
Travelled distance per time
Property of the medium (determined by the restoring force and the inertia)
For a wave propagating along a string under tension:
Where
Wave speed != speed of particle
Direction
Transverse: motion of medium perpendicular to direction of propagation
Longitudinal: motion of medium parallel to the direction of propagation
Types
- Mechanical
- Electromagnetic
- Gravitational
- Matter
Mechanical
Propagates through a physical medium
[!example] Sound, ocean wave
Electromagnetic
Propagate through the electromagnetic field
[!example] Light, radio
Representation
Snapshot: displacement as a function of position at a given moment in time
History graph: displacement as a function of time at a given point in space
3D: both time and space
+
The leading edge is in the direction of the wave in snapshot.
The leading edge always comes first (left) in history graph.
=> the snapshot and the history graph are reversed for a wave going right.