Sound Flashcards
Study of sounds
Acoustics
Sound travel in the form of longitudinal waves
Sound waves are mechanical waves
What is wave
Wave is a disturbance which propagates energy from one place to another place
Matladthuna ante disturbance chesthuna disturbance create chesthuna, disturb cheyakunda waves form avvavu, oka alahadi create chesthuna ala ayinapuduu energy anedi oka nundi inkodagariki velliddii energy ekada aithe zero avuddooo akkadidaka velli agipothadii, energy aipothadiii
What is Wavelength
Lamda , stationary waves teskuntuna,
The distance between 2 successive nodes
The distance between 2 successive nodes lambda / 2
Complete wave distance lamda
Time period
Time taken to complete one complete oscillation ,
Frequency
The no of waves or oscillations or vibrations formed in one second
Hertz
Reciprocal of frequency is called time period
Frequency= waves / second
The relationship between frequency and time period is inversely proportional
Frequency units
1/sec called hertz
1 khertx = 10 ^ 3 hertz
V velocity of sound wave
Frequency * wavelength
When sound enters from one medium to another medium then velocity , wavelength of a sound wave changes but frequency constant
Types of waves
Mechanical
Electro magentic
Mechanical waves requires medium,
Sound waves( liq Or gases, solid sound waves travel through air Robert boyel proved as sound waves are mechanical)
Electro mangetic waves
The waves not require medium they are called electro magentic waves, also called as light waves
Maxwell proved
Uv micro waves x rays gamma rays
Types of waves by direction
Longitudinal waves
Transvwese waves
Travel by Parallel sound waves bell horn vissle, spring waves
Compreeeions and rarefractions are fomeed in longitudinal
Travel by perpendicular
Light waves and string waves
Crest and trough are formed in transeverse waves
Types of sound waves according to frequency
Infrasonic less than 20 hz we are nit able to hear
Earth quakes
Communication bet elephants , rhinoceros 5 hz
Audible sounds 20 to 20000hz
Ultrasonic sounds
Above 20 k hz to
Dogs hear upto 50 k
Bats produce upto 1 lakh.
Dolphins
Ultrasonic waves used
Ultrasonography
To detect child growth
Kidney stones small pieces that easily through ureter
Used in Sonar
Sound navigation and ranging
Is used to identify how depth it went
For sending signals from one place to another
Dry cleaners and aeroplane washing
Washing machine,
For cleaning the itrrnal parts of wall clocks
Cataract treatment
Xerox and large screen
To kill bacteria in milk
Finger print reading machings
Attract fishes in ocean and seas
Ultrasonic are used to scatter the mosquitoes in the labourstories
These are used to get uniform mixtures
Echo
If the reflected the sound reaching back to the observer from a wall or obstacle
Conditions 16.5 / 17 mts
Persistence 1/10 sec
Working principle of sethascope
Hydrophone, to measure sound velocity in water
Sound velocity depends on
Medium
Temperature. Density
Direction
humidity
Sound velocity in medium
Air 331
Air with temperature 20 343
Water 1486
Iron 5130
glass 5500
Diamond 12000
Sound velocity is more in diamond
Light waves is less in diamond
Sound waves velocity in vaccum
Zero it has no medium
Solid > liquid>gases
Which has more sound velocity
Solid
Liquid
Gas
Hydrogen has more velocity throughgases
Sound velocity on temperature
V proportional to square root of temperature
Itemp incre vel incre
Temp decre velo decre
Per every 1 degree centrigrade 0.61 m/s perugunu
Sound velocity depend on density
If density incre then velocity decreas
Vice versa
Note point :
Sound velocity is more in hydrogen than all gases
Reason hydrogen has less density
Sound velocity in humidity
Humid air has more sound velocity than the dry air
Because humid air has less density
Intensity of sound depend
Amplitude
I proportionsl to A^2
Amplitude
The max displacement in a medium / wave is called amplitude
Amplitude measure by audiometer
Or soundmeter
Unit of the intensity of sound decibell
Whishoer db
Whisper 15 to 20
Seconds hand in wall clock 30
Normal talk 60
Sound pollution 80
Traffic 90
Car horn 110
Aeroplane 120
Gunfire 140
Gslv 250
Pitch of the sound
Frequncy,
Measured by tonometer
Male lion
Female mosquito
Female has high pitch of the sound
Mach number
Speed of the vehicle/ speed of the sound in air
Mach has no unit
Working principle of speed gun
Doppler principle
Is used to measure the over speed of vehicles
Doppler effect is used in radar
Radio and detecting and ranging
Doppler effect related both sound and light
