Question

Explanation Loudness , Pitch , Ultrasound , 3 application of sound.​

Answer 1

Explanation:

In human physiology and psychology, sound is the reception of such waves and their perception by the brain.[1] Only acoustic waves that have frequencies lying between about 20 Hz and 20 kHz, the audio frequency range, elicit an auditory percept in humans. In air at atmospheric pressure, these represent sound waves with wavelengths of 17 meters (56 ft) to 1.7 centimetres (0.67 in). Sound waves above 20 kHz are known as ultrasound and are not audible to humans. Sound waves below 20 Hz are known as infrasound. Different animal species have varying hearing ranges.

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Answer 2

$\huge\underline{\underline{\red{\textbf{Explanation : -}}}}$

››Loudness :-

The loudness of sound is a measure of the the sound energy reaching the ear per second .

The loudness of sound depends on the ${\underline{\red{\textrm{Amplitude}}}}$ of sound waves .

• Greater the amplitude of sound waves, louder the sound will be .

★ Note :

• The loudness of sound is measured in "Decibel" written as dB.

›› Pitch :-

pitch is that characteristic of sound by which can be distinguish between different sounds of the Same loudness.

• The pitch of sound depends on the ${\underline{\red{\textrm{Frequency}}}}$ of vibration.

• The pitch of sound is directly proportional to it's frequency.

›› Ultrasound :-

The sounds having too high frequency which cannot be heard by human beings are called ultrasonic sound or ultrasound .

★ Applications of ultrasound :

ultrasound waves have a very - high frequency due to which they can penetrate into matter to a large extent.

• 1) Ultrasound is used in industries for detecting flaws in metal blocks without damaging them.

›› The flaws like : industrial cracks,..etc in metal blocks are detected by using ultrasound.

• 2) Ultrasound is used to break kidney stones into fine grains (which then flushed out with urine).

• 3) Ultrasound is used in "sonar" apparatus to measure the depth of sea(or ocean).

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