In sound waves, particles always displace in the direction of the wave propagation and a plane can not be determined by the two parallel lines. In contrast to sound waves, light waves or transverse waves are electromagnetic waves that have coupled planes involving two components — an electric and a magnetic component that oscillates perpendicular to each other forming a plane.
Therefore, light waves can be polarised. Sound waves are mechanical waves that need a material medium for propagation.
These waves propagate through molecules present in the medium. In air medium, there is only one way in which the molecules can affect the neighboring molecules and that happens longitudinally. In solids, sound waves act as both longitudinal and transverse waves. Transverse sound waves in solids also known as shear waves or S-waves or elastic S-waves are the waves that travel through the body of an object and propagate only through an elastic or solid medium.
These behave like light waves as the particle oscillations are perpendicular to the direction of wave propagation. In contrast to longitudinal waves, the S-waves do not involve compression and expansion of the particle motion.
These waves are also termed as secondary waves because these were the second type of waves that the earthquake seismogram detected. For instance, in a musical instrument like guitar, when a string is plucked the oscillations in the solid string can be vertical, horizontal or any possible angle that is perpendicular to the string.
S-waves polarized in the horizontal direction are called SH-waves and those polarized in the vertical direction are called SV-waves. Sound waves are generated from a sound source that creates vibrations forming a wave.
These vibrations are exhibited by the molecules through which the sound travels just like the ripples in the pond. When you hit the bell, the bell vibrates and a pressure wave P- wave propagates outward from the vibrating bell. When this pressure wave comes in contact with another particle or object present in the medium, the same amount of vibration will be imparted to that object.
The wave can either diffract or reflect after hitting the object. When this wave reaches your eardrum, your eardrum vibrates with an equal amount of vibration so that you hear the same intensity of sound as created by the source object. In simpler words, when you hit a drum, the drum vibrates. This vibration makes the air molecules move as the sound waves travel from the source drum to the air which acts as a medium.
The air molecules now vibrate and reach your ears. This causes our eardrums to vibrate in the same pattern as the source object vibrated. Sound waves can travel in gas, liquid and solid medium but can not travel in a vacuum as they need molecules that carry the vibration. The speed of sound depends on the medium employed. Longitudinal waves cannot be polarised.
The reason that only transverse waves can be polarised is that their vibrations can potentially occur in all directions perpendicular to the direction of travel.
It is therefore possible to confine the vibrations to a single plane. Or put another way an unpolarised transverse wave is a 3D shape, it is therefore possible to confine it to a 2D shape a plane.
The vibrations of a longitudinal wave occur along a single line, it is therefore not possible to confine that to a plane, i.
Why can't sound waves be polarized? Physics Light and Reflection Color and Polarization. Daniel W. Nov 17, Other electromagnetic waves include the microwaves in your oven, radio waves, and X-rays.
Light waves are regarded as a varying electric field E coupled with a varying magnetic field B , at right angles to each other and to the direction of travel.
This is depicted in the animation below. An electromagnetic wave transports its energy through a vacuum at a speed of about 3. The whole family of electromagnetic waves extends from gamma rays of very short wavelength lower than 10 m to very long radio waves greater than 10 3 m.
Unlike transverse waves such as electromagnetic waves, longitudinal waves such as sound waves cannot be polarized.
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