Ultrasonic waves are sound waves transmitted above the human-detectable frequency range, usually above 20,000 Hz. They are used by some animals and in medical or industrial technological devices.Know More
Some ultrasound-emitting devices are used to silence barking dogs without hurting human hearing, because only dogs find the sounds intolerable. Similarly, some medical equipment for diagnosing health complications can produce ultrasonic sounds of 10 MHz and above. Such sounds do not harm human tissue.
Bats use high-frequency sounds to navigate and catch prey. The animals emit ultrasonic waves while moving at high speed and in pitch darkness. When the sounds are reflected back, bats can tell what exactly is in front of them.Learn more about Optics & Waves
Sound is generally classed as ultrasonic when its frequency exceeds 20,000 hertz. This is the upper range of humans' ability to perceive, though the ultrasonic range of frequencies extends upward into the millions of hertz.Full Answer >
Electromagnetic and mechanical waves differ in that electromagnetic waves are always longitudinal and do not require a known medium, while mechanical waves are either longitudinal or compression waves and require a medium. All known electromagnetic waves are also known as forms of light. An example of a longitudinal mechanical wave is a wave in water, while sound is an example of a compression wave.Full Answer >
Sound waves occur when an object vibrates and transfers that energy into the air or another medium. When a vibrating object moves forward, it compresses the air molecules in front of it, and when it moves backward, it leaves a gap where they can expand or rarefy. The vibration produces many of these compression and rarefaction pairs, which travel away from the source of the vibration through the air.Full Answer >
A transverse wave is one where the displacement of the medium in which the wave is travelling is perpendicular to its propagation. A pond ripple is an example of a transverse wave.Full Answer >