Sound Basics
What is sound produced by?
Vibrations of a body.
What determines loudness? Define.
Amplitude of vibration.
The largest displacement of a vibrating body on either side from its mean position.
A sound wave has a wavelength of 2 m and travels at 340 m/s. What is its frequency?
70 hz
Through which medium does sound travel fastest and why?
Solids
What determines pitch? Define and write its inverse value(define that as well)
Frequency of vibration.
The number of vibrations completed in 1 second
Time Period: The Time it takes to complete 1 vibration
The frequency of Sound A is 300 Hz, and Sound B has ratio to Sound 2:1. What is the frequency of B.
What would be the time period of B
600 hz
1/600 =
Why can’t sound travel through a vacuum?
Because sound requires a material medium to propagate.
What is the characteristic that allows us to distinguish two sounds of the same pitch and loudness?
Quality or timbre.
Wave A has an amplitude of 2 cm, and Wave B has an amplitude of 6 cm. How many times louder does Wave B appear compared to Wave A (approx.)?
9:1
What is the speed of sound in air, water and iron?
air - 330 m/s
water- 1500 m/s
iron - 5950 m/s
Why is a woman’s voice typically shriller than a man’s?
Her vocal cords have a higher tension and are closer to each other, therefore vibrating at a higher frequency.
A sound wave has a frequency of 500 Hz and travels at 350 m/s. What is its wavelength and time period?
0.002 seconds
Why do astronauts in space use wireless radio communication?
Because sound cannot propagate in a vacuum, and radio waves do not need a medium.
Write 3 features for each of the following
(a) Pitch
(b) Loudness
Decided by Ms.
Two sound waves travel in the same medium. Wave X has a frequency of 600 Hz and an amplitude of 3 units. Wave Y has a wavelength twice that of Wave X and an amplitude half. Compare:
Their frequencies
Their loudness
a = 300 hz
b = 4:1