List two differences between electromagnetic waves and sound waves.

Expert Answers
jerichorayel eNotes educator| Certified Educator

Sound waves and electromagnetic waves are physical manifestation of vibrations happening in the universe. These two phenomena are important in the advancement of science and technology on earth. Sound waves are vibration or pattern of disturbances caused by movement of energy travelling on a medium such as air, water or other solids. Basically, the vibrations disturb the first medium it touches and it disturb the next to it and so on. We are able to sense the sound because the sound waves move the air molecules until it touches our eardrums. These vibrations in our ears are perceived in the brain as sound. Electromagnetic waves are transverse waves that oscillate perpendicular to the direction of the energy transfer or direction. Electromagnetic waves can travel through a vacuum, meaning it does not need a media for it to flow. Not all electromagnetic waves can pass through a certain object. 

Sound waves: requires a medium
Electromagnetic waves: Don't need a medium

Sound waves: longitudinal waves
Electromagnetic waves: Transverse waves

atsuzuki eNotes educator| Certified Educator

Waves may be defined as vibrations that propagate in space carrying energy.

There are different kinds of waves in nature. 

1. Sound waves are waves that propagate in elastic mediums (mediums that can vibrate) like atmospheric air, metals, water, etc. They are classified as mechanical waves, because the sources that generate sound waves vibrate mechanically. As such, they require an elastic medium through which to propagate.

2. Wave oscillations may be longitudinal or transversal in relation to the direction of propagation of the wave. Sound waves are longitudinal, i.e., their vibrations are along the direction of propagation.

1a. Electromagnetic waves are produced by oscillating electric charges, that is, they are not mechanical vibrations but field (electric and magnetic) oscillations.

2a. Electromagnetic waves are transversal waves, that is, their electric and magnetic oscillations occur perpendicular to the direction of their propagation. 

electreto05 eNotes educator| Certified Educator

A sound wave is the transmission in space and time, of the mechanical oscillations produced by a source. An electromagnetic wave is the transmission in space and time of electric and magnetic fields, which are mutually generate each other during the propagation.

Sound waves are mechanical waves, and have, inter alia, the following differences with respect to electromagnetic waves:

1. Sound waves require an elastic medium to propagate from the source. Electromagnetic waves do not require a medium for propagation, can be transmitted even in the absolute vacuum.

2. Sound waves are longitudinal waves that is, are transmitted in the same direction of oscillation of the particles in the medium. Electromagnetic waves are transverse ie, the electric and magnetic fields, which are perpendicular to each other, oscillate perpendicularly to the direction of wave propagation.

nicole8923 | Student

Sound waves are waves of motion within their medium. Electromagnetic waves, however, do not need any medium to propagate. it is just basically raw energy. this raw energy can be viewed as packets, or photons, which act sort of like particles, or it can be viewed as waves which act without a medium. you should know the whole wave/particle duality thing, but aside from that, this type of radiation is a pretty nebulous concept. 

malkaam | Student

Electromagnetic waves are transverse waves, its examples are microwaves, radio waves, infra red, visible light, ultra violet, x rays etc. on the other hand sound waves are longitudinal waves.

Another difference is that electromagnetic waves can travel without a medium and can travel through a vacuum, whereas sound waves require a medium for travel and cannot travel through a vacuum.

ssarfraz | Student

A wave is a disturbance that travels through space and matter, accompanied by a transfer of energy.

For Example,

When we look at the pond, its surface is usually calm. Through a pebble in it, and it can be clearly seen that the ponds surface is disturbed. And that disturbance slowly spreads outward.

In short it can be said that waves are a pattern of disturbances caused by movement of energy through matter or space.

Electromagnetic Waves

Waves that does not need any medium or matter to travel through, and travels through space, are called electromagnetic waves.

Sound waves

Sound is a mechanical wave that results from the back and forth vibration of the particles of the medium through which the sound wave is moving.

Differences between Sound Waves And Electromagnetic Waves

  1. A Sound wave is a longitudinal wave whereas, electromagnetic waves are transverse waves.
  2. Sound is a mechanical vibration that passes through a medium such as gas, liquid or solid to become a sound. Whereas,Electromagnetic waves, also known as EM wave, is the travel path of electromagnetic radiation or EMR. EMR is a form of energy that is emitted and absorbed by charged particles.
  3. Sound waves need a medium to travel but electromagnetic wave does not need a medium to travel.
  4. Electromagnetic waves move with very high velocity in vacuum.
    but sound waves do not move with very high velocity in vacuum.
  5. Examples of Sound Waves are whistle, drum. Where as, example of electromagnetic waves are radio waves, light.
vhk521 | Student

To be a bit more specific, when sound waves are transmitted through a solid, it can be either longitudinal waves OR transverse waves. Sound waves being transmitted only as longitudinal waves only applies when the it is being transmitted through a non-solid medium, such as gas, liquid, or plasma. 

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