Introduction to Waves

Study Notes

Waves are disturbances or oscillations that carry energy from one point to another without transferring matter.
Waves propagate (move) transferring energy, but do not move objects.
Wave pulses are single vibrations.
Wave trains are continuous vibrations.
Transverse waves: particles vibrate perpendicular to the direction of wave propagation. Particles move up and down.
Longitudinal waves: particles vibrate parallel to the direction of wave propagation. Particles vibrate back and forth.

Surface waves are a combination of transverse and longitudinal waves. The particles move in circles.
Mechanical waves require a medium to travel (e.g., sound waves).
Electromagnetic waves do not require a medium to travel (e.g., light, radio).
Matter waves describes the wavelike properties of subatomic particles.

Mechanical waves travel slowest in less elastic and dense mediums.
The speed of mechanical waves depends on the properties of the medium (e.g., density, elasticity). Specifically, mechanical waves travel slowest in the least elastic and dense medium. Moving from least to most dense, wave speed increases for mechanical waves following this order: Vacuum<Gas<Liquid<Solid.
Electromagnetic waves travel at the speed of light (approximately 3 x 10⁸ m/s) in a vacuum. This is the fastest speed for any wave.

Wavelength (λ): Length of one oscillation, measured in meters.
Frequency (f): Number of waves passing a point per second, measured in Hertz (Hz).
Amplitude (A): Maximum displacement of a particle from its resting position, measured in meters.
Crest: Highest point of a wave.
Trough: Lowest point of a wave.
Equilibrium Position: Resting position of a particle.