Physics > Motion of Waves > 2.0 Mechanical waves
Motion of Waves
1.0 Introduction
2.0 Mechanical waves
2.1 Transverse waves
2.2 Longitudinal waves
2.3 Differences between transverse and longitudinal waves
3.0 Properties of wave motion
3.1 General equation of wave motion
3.2 Wave function
3.3 Equation of a plane progressive harmonic wave
3.4 Important relations
4.0 Speed of a transverse wave on a string
5.0 Energy associated with a wave
6.0 Questions
2.2 Longitudinal waves
2.2 Longitudinal waves
2.3 Differences between transverse and longitudinal waves
3.2 Wave function
3.3 Equation of a plane progressive harmonic wave
3.4 Important relations
In longitudinal waves, the particles of the medium oscillate along the direction of wave propagation.
For example: Sound waves in air
Note:
- Ultrasonic waves in air produced by a vibrating quartz crystal are longitudinal waves
- Waves produced in a cylinder containing a liquid by moving its piston back and forth are longitudinal waves
- In a vibrating tuning fork the waves in the prongs are transverse while in the stem are longitudinal
- Some waves in nature are neither transverse nor longitudinal but a combination of the two. For example: Waves produced by a motor boat sailing in water is a combination of both longitudinal and transverse waves
- The waves on the surface of water are of two types,
- Capillary waves
- Gravity waves
- Waves may be one dimensional, two dimensional or three dimensional according as they propagate energy in just one, two or three dimensions.
- Transverse waves along a string or longitudinal waves along a spring are one dimensional
- Surface waves or ripples on water are two dimensional
- Sound waves proceeding radially from a point source are three dimensional
