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The Intensity of Sound

Note and Tone

A sound of a single frequency is called a tone. A sound produced with a mixture of

several frequencies is called a note.

Quality of sound

The richness or timber of sound is called the quality. Sound with the same pitch and
loudness can be distinguished based on the quality. Music is pleasant to the ears

while noise is not. But they both can have the same loudness and pitch.

Speed of sound

Sound travels through different media with different speeds. Speed of sound
depends on the properties of the medium: pressure, density and temperature, wind

speed and nature of the medium.

On what factors do the speed of sound in a gas depends?

Ans. The speed of sound in a gas depends on the following factors:

1. Density. -The speed of sound in a gas is inversely proportional to the square root

of its density at constant pressure i.e., Speed of sound 1/ Density of gas

2. Temperature- speed of sound increases with the increase in temperature of the
gas. 3. Humidity- The speed of sound is directly proportional to humidity i.e.; sound

travels faster in moist air than in dry air.

4. Wind speed- The speed of sound increases when the wind blows in the direction

of sound and decreases when the wind blows in the opposite direction.

Speed of sound: Solids > Liquids > Gases

0
Speed of sound in air = 331 m/s at 0 C and 344 m/s at 22 C
∘
When a source emits sound with a speed greater than the speed of sound in air, it

creates a sonic boom which produces shockwaves with lots of energy. They produce

a very loud noise which is enough to shatter glass and damage buildings.

Ex- Jet aircrafts.