Mechanical vs Electromagnetic Waves
Mechanical waves end electromagnetic waves are two types of waves discussed in physics. Mechanical waves are waves that are caused by mechanical actions such as vibrations. Electromagnetic waves are waves created by oscillating electric and magnetic fields. These two types of waves are very important in understanding fields such as electromagnetism, waves and vibrations, optics, acoustics and many others. In this article, we are going to discuss what are mechanical waves and electromagnetic waves, their definitions, applications of mechanical waves and electromagnetic waves, similarities between these two and finally the difference between mechanical waves and electromagnetic waves.
Electromagnetic waves, more commonly known as EM waves, were first proposed by James Clerk Maxwell. This was later confirmed by Heinrich Hertz who successfully produced the first EM wave. Maxwell derived the wave form for electric and magnetic waves and successfully predicted the speed of these waves. Since this wave velocity was equal to the experimental value of speed of light, Maxwell also proposed that light was, in fact, a form of EM waves.
Electromagnetic waves have both an electric field and a magnetic field oscillating perpendicular to each other and perpendicular to the direction of wave propagation. All electromagnetic waves have the same velocity in vacuum. The frequency of the electromagnetic wave decided the energy stored in it. Later it was shown using quantum mechanics that these waves are, in fact, packets of waves. The energy of this packet depends on the frequency of the wave. This opened the field of wave – particle duality of matter. Now it can be seen that electromagnetic radiation can be considered as waves and particles. An object placed in any temperature above the absolute zero will emit EM waves of every wavelength. The energy at which the maximum number of photons is emitted depends on the temperature of the body.
Mechanical waves are waves that are created by mechanical processes. Waves such as sound waves, ocean waves and shock waves are some examples for mechanical waves. All mechanical waves require a medium to propagate. The energy of a mechanical wave depends on the amplitude of the wave.
A mechanical wave has several properties. Most important of these properties are velocity, amplitude frequency and wavelength. For any mechanical wave, the relationship v = f λ stands true; here, v is the wave velocity, f is the frequency, and λ is the wavelength.
What is the difference between Mechanical Waves and Electromagnetic Waves?
• Electromagnetic waves do not require any medium to travel whereas mechanical waves must have a medium to propagate.
• The energy of electromagnetic waves is quantized, but the energy of mechanical waves is continuous.
• The energy of the mechanical waves depends on the amplitude of the wave, but the energy of an electromagnetic wave depends only on the frequency.
• Electromagnetic waves display particle like behavior, but mechanical waves do not display such behavior.