Longitudinal and Transverse Waves

The motion of energy from one point to another point is known as waves. They are a disturbance that propagates energy through a medium. Particles tend to move as a wave or waves pass through any location. However, there is no net movement of the particle. What it means is that, once a wave is passed the particle returns to its original position.

In this way, we can also say that energy travels in a wave and not in a particle. Generally, a particle vibrates in its position and in this way energy propagates from one point to another.

If particle vibrates perpendicular to the direction of motion of wave then the wave is known as a transverse wave. Similarly, if particle vibrates along the direction of motion of wave the wave is known as a longitudinal wave.

Longitudinal Waves

In longitudinal waves, the particles transfer energy from one point to another by vibrating in the line of direction of propagation of the wave. In longitudinal waves, the movement of particles is usually parallel to the movement of energy.

Here, the particles are also displaced parallel to the direction of the travelling wave. An example of longitudinal waves is compressions moving along a slinky. We can make a longitudinal wave by pushing and pulling the slinky horizontally.

Longitudinal waves travel in the form of compression and rarefaction. The best example of longitudinal waves are sound waves.

Also Read: Types of Waves

Sound Waves

A single-frequency sound wave travelling through the air will cause a sinusoidal pressure variation in the air. The air motion which accompanies the passage of the sound wave will be back and forth in the direction of the propagation of the sound, a characteristic of longitudinal waves.

In space, no one can hear you even if you scream. And as scary as that statement may be, that shouldn’t be altogether surprising. If sound waves are vibrations in the air, then take away that air… and bye-bye vibrations.

Sound waves need a medium (or material) to travel through. These kinds of vibrational waves have another name: longitudinal waves. In fact, there are two main types of waves: transverse and longitudinal.

Also Read: Wave Motion

Scientists love to name things. It’s not enough to name the wave itself, we also need to name some of the wave’s features. Two of these are called compressions and rarefactions.

Compression is a high-density part of the wave (the part where the slinky is compressed). It is the peak of the wave. A rarefaction is a low-density part of the wave (the part where the slinky is most spread out). This is the trough of the wave.

Transverse Waves

In transverse waves, the particles transfer energy from one point to another point by vibrating perpendicularly in the direction of the propagation of the wave. What it means is that in transverse waves movement of particles are at right angles to the movement of energy.

In a transverse wave, the particles are displaced perpendicular to the direction that the wave travels. Examples of transverse waves include vibrations on a string and ripples on the surface of the water. We can make a horizontal transverse wave by moving the slinky vertically up and down. Radio wave, water waves are a few examples of transverse waves.

Waves produced in a string is a good example of a transverse wave. Transverse waves have what are called peaks and troughs. The peak is the crest or top point of the wave and the trough is the valley or bottom point of the wave. Waves produced in a string are standing waves.

Light waves are electromagnetic waves and all electromagnetic waves are an example of transverse waves.

Difference Between Longitudinal and Transverse Waves

Transverse Longitudinal
The movement of the particle is perpendicular to the direction of wave The movement of the particle is along the direction of the wave
Consists of troughs and crests It contains refractions and compressions
Travels only in solids. Can travel through all states of matter.
Light waves are transverse waves. Sound waves are longitudinal waves.
The particles are displaced perpendicular to the direction of the travelling wave. The movement of particles is usually parallel to the movement of energy.

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