Question

In: Physics

Two sources emit sound with the same frequency. One source is at rest and the other...

Two sources emit sound with the same frequency. One source is at rest and the other is moving at a rate of 5 m / s toward the stationary observer. Observers hear kites 6 times per second. Determine the frequency of the sound emitted by the source.

Expert Solution

Doppler's effect states that the frequency perceived by an observer changes if there is a relative motion between the source and the observer.

f ' = ( V-Vo / V- Vs ) * f ------------- formula 1

where f ' is apparent frequency heard by the observer, f is the frequency of the source, V is speed of sound ,Vo is speed of observer and Vs is speed of source . In this formula the sign convention is that speed will be taken as positive if it is in the direction : from source to observer .

GIVEN : 1) Velocity of source 1 ( Vs1) = 5 m/s

2) Velocity of source 2 (Vs2)= 0 m/s

3) Velocity of observer ( Vo)= 0m/s

4) taking frequency of souces = F

Taking velocity of sound = 340 m/s

Observer hears kites 6 times per second which means we have the beat frequency given to us as 6 Hz.

formula of beat frequncy is modulus of ( F1 - F2 ) where F1 and F2 are the frequency of sources interfering to produce the beat.

We know that by doppler's effect observer will hear frequency F from Source 2 as there is no relative motion because Vs2 and Vo both are 0.

by doppler's effect the apparent frequency heard by observer from source 1 is F "

by appluing formula 1 : F'' = ( 340 - 0 / 340 - 5 ) * F

we get F '' = 1.0149 * F

now we know that our beat frequency is 6 Hz

applying formula of beat frequency ie. F'' - F = 6 Hz

1.0149 F - F = 6

0.0149 F = 6

F= 6 /0.0149 = 402.6 Hz

We get the frequency of sources to be F= 402.6 Hertz.

Hope it helps!

Any feedback would be greatly appreciated .

genius_generous answered 2 years ago

(numbers 20-21) Two speakers emit the same pure tone (sound of a single frequency) and are...

(numbers 20-21) Two speakers emit the same pure tone (sound of a single frequency) and are in phase. 20. An observer begins at the center point between the speakers and slowly moves toward one of the speakers. The second very quiet spot encountered (completely destructive interference) is 1.5 m from the center. What is the wavelength of the sound? a) 1.0 m b) 1.5 m c) 2.0 m d) 2.5 m e) 3.0 m 21. If the distance between the...

Two loudspeakers, 1.1 mm apart, emit sound waves with the same frequency along the positive xx-axis....

Two loudspeakers, 1.1 mm apart, emit sound waves with the same frequency along the positive xx-axis. Victor, standing on the axis to the right of the speakers, hears no sound. As the frequency is slowly tripled, Victor hears the sound go through the sequence loud-soft-loud-soft-loud before becoming quiet again. What was the original sound frequency? Assume room temperature of 20∘C∘C. Express your answer with the appropriate units. please write the answer neatly, another post similar to this one was difficult...

Two speakers face each other, and they each emit a sound of wavelength (lambda). One speaker...

Two speakers face each other, and they each emit a sound of wavelength (lambda). One speaker is 180 (degrees) out of phase with respect to the other. If we separate the speakers by a distance1.5 (lambda),how far from the left-most speaker should we place a microphone in order to pick up the loudest sound? Ignore reflections from nearby surfaces. Select all that apply. 3/4 lambda 0 lambda 1/2 lambda 1/4 lambda 1 lambda

(1) (A)You approach a stationary sound source with a speed such that the frequency of sound...

(1) (A)You approach a stationary sound source with a speed such that the frequency of sound you hear is 17% greater than the actual frequency. With what speed are you approaching the sound source? Use the speed of sound in air as 343 m/s. (B)Two trains approach each other on separate but adjacent tracks. Train 1 is traveling at a speed of 31.9 m/s and train 2 at a speed of 27.6 m/s. If the engineer of train 1 sounds...

Two in-phase loudspeakers, which emit sound in all directions, are sitting side by side. One of...

Two in-phase loudspeakers, which emit sound in all directions, are sitting side by side. One of them is moved sideways by 3.0 m, then forward by 7.0 m. Afterward, constructive interference is observed 14, 12, and 34 the distance between the speakers along the line that joins them, and at no other positions along this line. What is the maximum possible wavelength of the sound waves? Express your answer with the appropriate units.

If a sound with frequency fs is produced by a source traveling along a line with...

If a sound with frequency fs is produced by a source traveling along a line with speed vs. If an observer is traveling with speed vo along the same line from the opposite direction toward the source, then the frequency of the sound heard by the observer is fo = c + vo c − vs fs where c is the speed of sound, about 332 m/s. (This is the Doppler effect.) Suppose that, at a particular moment, you are...

Two speakers spaced a distance 1.5 m apart emit coherent sound waves at a frequency of 680 Hz in all directions. The waves start out in phase with each other.

Two speakers spaced a distance 1.5 m apart emit coherent sound waves at a frequency of 680 Hz in all directions. The waves start out in phase with each other. A listener walks in a circle of radius greater than 1 m centered on the midpoint of the two speakers. At how many points does the listener observe destructive interference? The listener and the speakers are all in the same horizontal plane and the speed of sound is 340 m/s....

Two point source three meter apart are driven by the same oscillator at a frequency of...

Two point source three meter apart are driven by the same oscillator at a frequency of 800 hz. The sources emit energy in the form of spherical waves. An observer initially hears a maximum at a distance 10 m along the perpendicular bisector of the line joining the two sources. What distance (in m) must observer move along a line parallel to the line joining the two sources before reaching a minimum intensity? (Assume the speed of sound is 343...

Problem 6: Two students are standing the same distance from a source of sound. The first...

Problem 6: Two students are standing the same distance from a source of sound. The first student receives a power of 246 × 10-6 W in their eardrum. The second student receives σ = 1.17 times more power in their eardrum. Part (a) What is the ratio of the diameters of the student's eardrums? Part (b) If the second student's eardrum has a diameter of d = 1 cm what was the intensity of the sound that the student heard,...

The sound source of a ship’s sonar system operates at a frequency of 22.0 kHz ....

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∘C) is 1482 m/s . What is the difference in frequency between the directly radiated waves and the waves reflected from a whale traveling straight toward the ship at 4.95 m/s ? Assume that the ship is at rest in the water. Your target variable is Δf, the magnitude of the difference...