Mechanical waves are classified as longitudinal waves and transverse waves. Some examples of longitudinal waves are sound waves, seismic P waves, and ultrasound waves.
Transverse waves examples include electromagnetic waves and ocean waves. In this article, we will learn what is a longitudinal wave and its characteristics.
What Is a Longitudinal Wave?
Longitudinal waves are waves where the displacement of the medium is in the same direction as the direction of the traveling wave.
The distance between the centers of two consecutive regions of compression or the rarefaction is defined by wavelength, λ.
When the compression and rarefaction regions of two waves coincide with each other, it is known as constructive interference and if the regions of compression and rarefaction do not coincide, it is known as destructive interference.
Real Life Examples of Longitudinal Waves
1. Sound waves in air:
When we speak or play loud music this generates a vibration and this vibration creates a longitudinal wave in the surrounding air, and because of this wave, we receive a sound from a distance.
2. Primary waves (P-waves) of an earthquake:
How many of you experience an earthquake? If you experience it then you know it generates the vibration and it goes in one Parallel direction. This happens because of the seismic waves it is a type of Longitudinal wave that travels through the earth’s interior, which causes the ground to oscillate in the parallel direction of the wave propagation.
3. Ultrasound:
Many of us are familiar with the Ultrasound that is done in hospitals and some of us may be experiencing it as well. Well, this is an imaging technology that uses ultrasound waves. This is a type of wave that Consists of Compression and rarefaction, which makes ultrasound waves longitudinal.
4. Vibration of a spring:
If we stretch or compress the spring and then release it, so we see that the spring undergoes a Series of Oscillations. This creates a Compression and rarefaction in the spring which create the longitudinal waves.
5. Fluctuations in a gas:
In gases, longitudinal waves are formed by compressing and expanding their gas particle. As we see above sound waves in the air are examples of this phenomenon because they use the air (gas).
6. Tsunami waves:
Tsunamis are typically generated by underwater earthquakes or volcanic eruptions. The waves generated are longitudinal waves that propagate through the ocean, causing massive oscillations in sea level.
7. Speaking on the mic
A sound wave is a significant example of a longitudinal wave. When a speaker speaks some words in front of the microphone, he/she hits the air thousands of times per second at different frequencies. The sound particles travel along with the air particles and enter the mic to produce sound.
8. Clapping
When we clap while singing a birthday song or on any other occasion, do you know, what makes our hand produce that familiar sound of a clap? When we applaud, we compress and displace the air particles between our hands for a part of a second, which produces the sound of a clap we are familiar with.
9. Vibrating Drumheads
All of us are familiar with the sound of a drum, and most of us have also tried hitting the drum in different beats. When we hit the drum with the mallet, the drum head vibrates and produces sound waves. The soundwaves are generated because the drum head moves outward and inward, making air particles move (vibrate) in the same direction.
10. Vibration in Window Panels after a Thunder
Whenever it is raining heavily, and thunders are there, you might have noticed the vibration in the window panels of your home; it happens because of sound waves. Lightning causes an increase in the air pressure and temperature, which creates a shock wave of sound that we hear like a loud boom and cause our window panels to vibrate.
11. Music Woofers
Have you ever noticed the movement of the woofer cone; moving in and out or ever felt air pressure on your hand when you try to cover the mouth of a woofer? It’s because woofers work on the phenomenon of a longitudinal wave. They move the air particles in or out, producing sound.