Problem 12.75 The sound source of a ship\'s sonar system operates at a frequency
ID: 1468527 • Letter: P
Question
Problem 12.75
The sound source of a ship's sonar system operates at a frequency of 22.0 kHz . The speed of sound in water (assumed to be at a uniform 20.0 C) is 1482 m/s .
Part A
What is the wavelength of the waves emitted by the source?
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Part B
What is the difference in frequency between the directly radiated waves and the waves reflected from a whale traveling straight toward the ship at 4.80 m/s ? The ship is at rest in the water.
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Problem 12.75
The sound source of a ship's sonar system operates at a frequency of 22.0 kHz . The speed of sound in water (assumed to be at a uniform 20.0 C) is 1482 m/s .
Part A
What is the wavelength of the waves emitted by the source?
= mSubmitMy AnswersGive Up
Part B
What is the difference in frequency between the directly radiated waves and the waves reflected from a whale traveling straight toward the ship at 4.80 m/s ? The ship is at rest in the water.
f = HzSubmitMy AnswersGive Up
Explanation / Answer
relation between the wavelength L and frequency f is
V = Lf
where V is speed of the sound
so
L = V/f = 1482/22000
L = 6.73 cm
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waves from a stationary sonar with a frequency
f' = (V+Vw)f/v
and whne refiects
f'' = V f'/(V-Vw)
difference of frequency
df= f'-f '' = 2Vw/(V-Vw)
df =22000 * 2* 4.8/(1482 - 4.8)
df = 142.78 Hz