Given, g = 10 m s –2 . and speed of sound = 340 m s –1 .
What is sound in physics in 9th class?
Sound is a mechanical energy which produces sensation of hearing. Sound is produced due to vibration of different objects. • Sound wave propagates as compressions & rarefactions in the medium. Sound waves are longitudinal waves.
What is 9 9th class sound?
Sound is defined as vibrations that travel through air or another medium as an audible mechanical wave. It is produced from a vibrating body. The vibrating body causes the medium (water, air etc.) around it to vibrate these producing sounds.
How many types of sound are there in class 9?
As given in the solutions for science NCERT class 9, there are 5 characteristics of sound, namely Frequency, Wavelength, Amplitude, Time Period, and Velocity.
What is production of sound class 9?
Production of Sound Sound is produced due to the vibration of objects. Vibration is a periodic back-and-forth motion of the particles of an elastic body or medium about a central position. It is also named as oscillation. For example: Stretched strings of a guitar vibrate to produce sound.
How is sound produced PDF?
How is Sound Produced? Sound is produced when an object vibrates, creating a pressure wave. This pressure wave causes particles in the surrounding medium (air, water, or solid) to have vibrational motion. As the particles vibrate, they move nearby particles, transmitting the sound further through the medium.
What is the SI unit of sound?
Since this energy can be measured, the most common SI unit of sound that is used is Decibel which is abbreviated as dB. This unit is basically used to express the ratio of some value of a physical property to another, mainly on a logarithmic scale. This is called as Decibel Scale or DB Scale.
What are the types of sound?
- Inaudible sounds are sounds that the human ear cannot detect. The human ear hears frequencies between 20 Hz and 20 KHz.
- Sounds that are below 20 Hz frequency are called Infrasonic Sounds.
- Sounds that are above 20 KHz frequency are called Ultrasonic Sounds.
Is sound a physics chapter?
CBSE Class 9 Physics, SoundExplore More. Sound is a mechanical energy which produces sensation of hearing. Sound is produced due to vibration of different objects. Sound wave propagates as compressions & rarefactions in the medium.
What is sound short answer?
Sound is defined as vibrations that travel through the air or another medium as an audible mechanical wave. It is produced from a vibrating body. The vibrating body causes the medium (water, air, etc.) around it to vibrate thus producing sound.
What are the features of sound?
The five characteristics of sound are amplitude, wavelength, period, frequency, and speed or velocity.
How is sound produced?
What is called sound?
Sound is a type of energy made by vibrations. When an object vibrates, it causes movement in surrounding air molecules. These molecules bump into the molecules close to them, causing them to vibrate as well. This makes them bump into more nearby air molecules.
Why is sound called longitudinal wave?
Sound waves in air (and any fluid medium) are longitudinal waves because particles of the medium through which the sound is transported vibrate parallel to the direction that the sound wave moves.
What does Hz mean in sound?
High frequencies produce more oscillations. The units of frequency are called hertz (Hz). Humans with normal hearing can hear sounds between 20 Hz and 20,000 Hz. Frequencies above 20,000 Hz are known as ultrasound.
What are the 4 properties of sound?
Since sound is a wave, it has all of the properties attributed to any wave, and these attributes are the four elements that define any and all sounds. They are the frequency, amplitude, wave form and duration, or in musical terms, pitch, dynamic, timbre (tone color), and duration.
What kind of wave is sound?
Longitudinal waves A longitudinal wave is one where all the particles of the medium (such as gas, liquid or solid) vibrate in the same direction as the wave. Sound waves are longitudinal waves.
Does sound carry energy?
Solids, liquids, and gases all transmit sound as energy waves. Sound energy is the result when a force, either sound or pressure, makes an object or substance vibrate. That energy moves through the substance in waves. Those sound waves are called kinetic mechanical energy.
What is the formula of sound?
If the temperature is TC = 20 °C (T = 293 K), the speed of sound is v = 343 m/s. The equation for the speed of sound in air v = √γRTM can be simplified to give the equation for the speed of sound in air as a function of absolute temperature: v=√γRTM=√γRTM(273K273K)=√(273K)γRM√T273K≈331m/s√T273K. v=fλ.
What is dB noise level?
It is measured in decibels (dB). The decibel scale is logarithmic, which means that loudness is not directly proportional to sound intensity. Instead, the intensity of a sound grows very fast. This means that a sound at 20 dB is 10 times more intense than a sound at 10 dB.
What is unit of velocity?
The SI unit of velocity is metre per second (m/s). Alternatively, the velocity magnitude can also be expressed in centimetres per second (cm/s).
What are the 3 properties of sound?
We will look in detail at three fundamental characteristics of sound: speed, frequency, and loudness.
Who discovered sound?
The origin of the science of acoustics is generally attributed to the Greek philosopher Pythagoras (6th century bc), whose experiments on the properties of vibrating strings that produce pleasing musical intervals were of such merit that they led to a tuning system that bears his name.
What are uses of sound?
- Communication. For many animals including us, sound is a main form of communication.
- Enhancing Cell Growth.
- Being Unique.
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What is a sound in physics?
sound, a mechanical disturbance from a state of equilibrium that propagates through an elastic material medium.