6/18/2023 0 Comments Wave definition physics scienceThe region of minimum density of medium in a longitudinal wave, is called rarefaction. The region of maximum density of medium in a longitudinal wave, is called compression. This wave can be graphically represented as: A moving sound wave produces compressions (regions of more density and pressure) and rarefactions (regions of less density and pressure) alternately at regular time intervals. Sound waves are of longitudinal type because these make the particles of the medium vibrate in the direction in which wave travels. So the sound waves never reach the earth. If some explosion takes place on moon, sound of the explosion will not be propagated to the earth. The space above the atmosphere is also vacuum. In the absence of medium (air) around the source, sound is not being propagated.Ī natural fact : Moon has no atmosphere. After sometime no sound is heard, though the bell hammer is seen in vibration. With decrease air inside the jar, sound heard becomes weaker and weaker. The vacuum pump is started and the air from inside the jar is gradually drawn out. Initially when jar has normal air inside it, sound waves produced by the ringing bell heard outside the jar. The bell is connected to a battery through a key. A pipe through the hole leads out to a vacuum pump (pump which draws the air out of a vessel). The jar is closed at the bottom by an airtight plate with a hole in the centre. SOUND NEEDS A MATERIAL MEDIUM FOR ITS PROPAGATION :Īn electric bell is enclosed inside an inverted bell jar by hanging from the rubber cork. A wave is a disturbance which travels through a medium due to the vibratory motion of the particles of the medium. These vibrating air molecules, in turn pass on their vibrations to the neighbouring air molecules and in this manner, sound travels to the listener in the form of waves. The vibrating string of a musical instrument or the vibrating prongs of the tuning fork, set the molecules of the air surrounding them into vibration. When the vocal cords are tight and thin, the type or quality of voice is different from that when they are loose and thick. Muscles attached to the vocal cords can make the cords tight or loose. When the lungs force air through the slit, the vocal cords vibrate, producing sound. Two vocal cords are stretched across the voice box or larynx in such a way that it leaves a narrow slit between them for the passage of air. This part of the body is known as the voice box. Put your fingers on the throat and find a hard bump that seems to move when you swallow. ![]() ![]() ![]() In humans, the sound is produced by the voice box or the larynx. Musical instruments and their vibrating parts :.In laboratory, sound is produced by a tuning fork when beaten with rubber pad, by plucking a stretched string of violin, by striking tabla, by blowing flute etc. This is what characterizes sound waves in air as longitudinal waves. The motion of the particles is parallel (and anti-parallel) to the direction of the energy transport. If a sound wave is moving from left to right through air, then particles of air will be displaced both rightward and leftward as the energy of the sound wave passes through it. 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. It can be thought of as a series of interacting particles. The medium is simply the material through which the disturbance is moving. This sensation is produced by longitudinal waves in an elastic medium.Ī wave can be described as a disturbance that travels through a medium, transporting energy from one location to another location. Sound is a form of energy which produces the sensation of hearing.
0 Comments
Leave a Reply. |