Sound must travel through matter because it needs the vibration of molecules to propagate because outer space is a vacuum with no matter, it's very quiet the matter that transports the sound is called the medium. Atoms can stick or bond together in certain permissible combinations to form groups of atoms called molecules in the in the element sulphur, atoms group together to form rings of 8 atoms. A sound wave is a wave of alternating high-pressureand low-pressure regions of air sound is a longitudinal wave, meaning that the motionof particles is along the direction of propagation 13. Let's talk about sound waves, sounds waves are actually very kind of strange things to go through and think about how they work and part of the reason for that is they're associated with really small displacements of lots and lots of atoms and molecules that go back and forth, back and forth many, many times per second. A cartoon video of molecules in a sound wave illustrates the way a sound wave propagates (197 kb - this one takes patience the full file has to load and be digested before the real animation begins if you don't see concentrated bands of molecules moving to the right, it isn't doing its thing.
Sound vibrations can be thought of as waves moving through molecules low-pitched sounds have big gaps between waves, while high-pitched sounds have waves that are bunched together loud sounds have more molecules moving and more energy than soft sounds. The sound wave only becomes apparent when you look at the large-scale pattern of density variations the other weird thing about the animation is that the molecules stop moving and turn around without colliding with anything. The goal is to make sure the hose is touching the actual speaker so that when the speaker produces sound (vibrates) it will vibrate the hose set up your camera and switch it to 24 fps the higher.
Sound is a mechanical vibration sound is a regular mechanical vibration that travels through matter as a waveform it consists of longitudinal or compression waves in matter. As the air molecules move in the same direction as the wave, sound waves are therefore longitudinal waves the wavelength of a sound wave is the distance between successive compressions or rarefactions as shown in the diagram below. Sound arrow the dog barks his bark makes the air go between compressed and rarefied: the air molecules bounce back and forth a bit but don't really travel anywhere we call that type of wave longitudinal, like this.
Sticking with the sound-wave example, we might be interested in 'how loud' such a wave is loudness has to do with ampltitude or intensity - 'how compressed / how rarefied' the air molecules are this is often measured using the decibel scale. Sounds: allow the wave to expand here is a wave in two dimensions imagine the red dots are air molecules when you press play, the yellow dot at the center is going to suddenly expand and collapse. Sound waves are produced by vibration that causes the molecules of a medium to form alternating high- and low-pressure fronts these waves can travel through solids, liquids and sufficiently dense gases. These molecules are part of a medium, which is anything that carries sound sound travels through air, water, or even a block of steel, thus, all are mediums for sound without a medium there are no molecules to carry the sound waves.
Since air molecules (the particles of the medium) are moving in a direction that is parallel to the direction that the wave moves, the sound wave is referred to as a longitudinal wave the result of such longitudinal vibrations is the creation of compressions and rarefactions within the air. Thunder is the sound created by the quick movement of the heated air — a sound wave light travels at 186,000 miles per second (299792458 km/s) the speed of sound can vary depending upon many properties , including temperature and humidity , but 760 miles per hour (340 m/s) on a normal spring day is widely accepted. Sound is a disturbance caused by variations in pressure that travels as longitudinal waves through a medium such as air or water, disturbing molecules along the way the study of sound is known as acoustics.
Sound is produced when an object vibrates due to vibrations of the object, the molecules (or particles) of air surrounding the object also start vibrating with the same frequency the molecules vibrate along the direction of motion of the object the motion is communicated by each molecule to the. Sound waves travel through air in much the same way as water waves travel through water in fact, since water waves are easy to see and understand, they are often used as an analogy to illustrate how sound waves behave. The moving air molecules bump into your eardrum, and you hear the vibrations as sound tell the audience that we can use a laser to show them what sound vibrations look like take the laser pointer and show them how you can make a line on the screen by moving your hand back and forth quickly.
Sound waves are energy moving from one place to another through a medium, but the molecules of the medium — for example, the air or water molecules — do not move with the wave but merely vibrate to transfer the energy along. The smallest wavelength within the audio spectrum is about 2 cm (the maximum possible frequency in air is discussed below) we can select a cube of air a thousand times smaller than this in width and it will still contain over 2x10 11 molecules. Molecules of different weight (other gases maybe) or different velocity (that translates into temperature) will exhibit different speeds of sound motion of the sound source, the listener, or the air itself has no effect on the speed of sound, nor does the pressure of the air.