Sound (Physics)

Seismic waves are vibrations in the Earth that transmit energy and occur during seismic activity such as earthquakes, volcanic eruptions, and even man-made explosions. There are two types of seismic waves, primary waves and secondary waves.

Primary waves, also known as P waves or pressure waves, are longitudinal compression waves similar to the motion of a slinky. Thus, in P waves, the individual particles vibrate to and fro in the direction of wave propagation.

P waves can travel through liquids, solids and gases. Secondary waves, or S waves which can only travel through solids, are slower than P waves and therefore, in a seismograph, P waves are recorded earlier than S waves.

The motion of secondary waves is perpendicular to the direction of the wave travel, similar to the motion of vigorously shaking a rope Thus, in S waves, the particles vibrate up and down at right angles to the direction of wave propagation. Hence, both statements are correct.

Sound waves are divided into three categories that cover different frequency range; Audible waves (20 Htz- 20,000 Htz), Infrasonic waves (<20 Htz) and Ultrasonic waves (>20,000 Htz).

Ultrasonic waves are used to destroy insects, clean clothes by removing dust, treat diseases, control automatic doors, detection of aircraft and submarine, determination of depth of sea etc.

Sound waves are divided into three categories that cover different frequency range; Audible waves (20 Htz- 20,000 Htz), Infrasonic waves (<20 Htz) and Ultrasonic waves (>20,000 Htz).

Ultrasonic waves are used to destroy insects, clean clothes by removing dust, treat diseases, control automatic doors, detection of aircraft and submarine, determination of depth of sea etc.

The sound that can be audible to humans has a frequency ranging from 20 Hz to 20,000 Hz.

Audible range of sound for human beings is approximately 20 Hz to 20 kHz (20,000 Hz). Sound waves with frequencies higher than 20 kHz (20,000 Hz) are called ultrasonic waves (ultrasound).

In earthquake, infrasounds (less than 20 Hz) are produced before main shock waves. Hence, all three statements are incorrect.

Sonography or ultrasonography is an important mean of clinical diagnosis. It is a diagnostic imaging technique based on the application of ultrasound (ultrasonic waves).

It is widely used in the field of medical science. It is mainly used to provide a variety of information about the health of the mother during pregnancy, and the health and development of embryo or foetus.

Sonography or ultrasonography is an important mean of clinical diagnosis. It is a diagnostic imaging technique based on the application of ultrasound (ultrasonic waves).

It is widely used in the field of medical science. It is mainly used to provide a variety of information about the health of the mother during pregnancy, and the health and development of embryo or foetus.

Bats are a fascinating group of animals. They are one of the few mammals that can use ultrasonic sound to navigate. As they fly, make an ultrasonic (shouting) sound.

The returning echoes give the bats information about anything that is ahead of them, including the speed and size of an insect and which way it is going. This system of finding prey is called echolocation-locating things by their echoes.

The heart vibrates at infrasonic sound. We can hear them with the help of stethoscope. The speed of sound in solid is maximum. Mach number is a quantity that defines how quickly an object travels with respect to the speed of sound.

The Mach number (M) is simply the ratio of the object's velocity (V) divided by the speed of sound at the altitude (a). Ultrasonic is the name given to sound waves that have frequencies greater than 20,000 Hz. Therefore, statement 1, 3 and 4 are correct.

Stethoscopes work by the principle of multiple reflection of sound. When a doctor or nurse places a stethoscope diaphragm on a patient's chest, sound waves traveling through the patient's body cause the flat surface of the diaphragm to vibrate and because the vibrating object is attached to a tube, the sound waves are channeled in a specific direction.

Each wave bounces, or reflects, off the inside walls of the rubber tube, a process called multiple reflection. In this way, each wave, in succession, reaches the eartips, or rubber nubs on the ends of the device, and finally the listener's eardrums.