Mechanical Waves: Transverse Waves And Longitudinal Waves

Waves in physics mean an oscillation about a fixed axis or a point that is accompanied by a transfer of energy that travels through the medium such as space or mass. When the transfer of energy takes place through a medium due to oscillation, the resultant wave can be termed as a mechanical wave.

The distance of the wave’s propagation is limited by the medium of transmission. In this case, the oscillating material moves about a fixed point and there is very little translational motion. One interesting property of mechanical waves is the way they are measured, given by displacement divided by wavelength. This dimensionless factor when it reaches 1, results in the generation of harmonic effects; for example, waves break on the beach when this factor exceeds one, resulting in turbulence.


Types of mechanical waves

Mainly there are two types of mechanical waves, namely:

  • Transverse Waves
  • Longitudinal Waves

What Are Transverse Waves?

In transverse waves, the displacement of the particle is perpendicular to the direction of propagation of the wave. You can see in the picture how the just the up and down motion of the particles in the wave results in the movement of the waves sideways.

Transverse Waves

Examples Of Transverse Waves

In transverse waves too, the particles do not move along with the wave. They just move up and down about their equilibrium positions. Some examples of transverse waves are:

  • The ripples on the surface of the water
  • The secondary waves of an earthquake
  • Electromagnetic waves
  • The waves on a string
  • Stadium or human wave
  • The ocean waves

Interested to learn more about other concepts related to waves, below is the link:

Gravity Waves

Gravity waves are also known as gravitational wave and are defined as the ripples caused in the space. It is caused due to various reasons like two huge stars orbiting each other or the explosion of stars asymmetrically.

Sound Waves – Medium For Their Propagation

Sound waves are the mechanical waves and are defined as the motion of waves with compressions (high-pressure region) and rarefaction (low-pressure region).

What Are Longitudinal Waves?

In a longitudinal wave, the displacement of the particle is parallel to the direction of the wave propagation. What you see in the picture is the wavefront progressing forward and the particles compressing and expanding in the same direction. This kind of wave is marked by periodic compression zones and rarefaction zones, where the medium expands.

Examples Of Longitudinal Waves

The particles in the wave do not move along with the wave though, they simply oscillate back and forth about their own equilibrium. Some examples of longitudinal waves are:

  • Sound waves in air
  • The primary waves of an earthquake
  • Ultrasound
  • The vibration in a spring
  • The vibration in a gas
  • The tsunami waves

longitudinal Waves

Stay tuned with BYJU’S to learn more about waves, oscillation and many more with interactive videos.


Practise This Question

Velocity of sound in air is 332ms1. Its velocity in vacuum will be