# A sound source producing 1.00-{\rm kHz} waves moves toward a stationary listener atone-half the speed of sound. The frequency that the listener will hear is2000 Hz. when the source is stationary and the listener moves towardthe source at one-half the

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1. ### physics pls help

A sound source producing 1.00-{\rm kHz} waves moves toward a stationary listener atone-half the speed of sound. The frequency that the listener will hear is2000 Hz. when the source is stationary and the listener moves towardthe source at one-half the speed of sound, the ...
2. ### physics

The Doppler effect occurs when a) a source of sound moves toward a listener b) a listener moves toward a source of sound c) a listener and a source of sound move away from each other d) a listener and a source of sound move toward each other. e) all of the above e--all of the ...
3. ### physics

1)As a sound source moves away from a stationary observer, the number of waves will. decrease 2)How fast should a car move toward you for the car's horn to sound 2.88% higher in frequency than when the car is stationary? The speed of sound is 343 m/s. fs(v-vd/v-vs) 343(1/1-987...
4. ### science

apparent change in wavelength of sound waves is 2.5cm when the source of sound is approaching stationary listener with velocity 8cm/s.Apparent decrease in the frequency of source when observer recedes from the same source at rest with a velocity of 30m/s is (velocity of sound...
5. ### physics

1)As a sound source moves away from a stationary observer, the number of waves will. A)increase B)decrease C)remain the same D)need to know the speed of the source (answer:decrease.) As the detector recedes from the source, the relative velocity is smaller, resulting in a ...
6. ### physics

1)As a sound source moves away from a stationary observer, the number of waves will. decrease 2)How fast should a car move toward you for the car's horn to sound 2.88% higher in frequency than when the car is stationary? The speed of sound is 343 m/s. fs(v-vd/v-vs) 343(1/1-987...
7. ### Physics

1)As a sound source moves away from a stationary observer, the number of waves will. A)increase B)decrease C)remain the same D)need to know the speed of the source (answer:decrease.) As the detector recedes from the source, the relative velocity is smaller, resulting in a ...
8. ### physics

if a man moving away with the speed of 0.5 of sound from a stationary sound source producing a sound of frequency , he would hear a sound of frequency
9. ### science

apparent change in wavelength of sound waves is 2.5cm when the source of sound is approaching stationary listener with velocity 8cm/s.
10. ### physics

An airplane traveling at v = 163 m/s emits a sound of frequency 1730 Hz. At what frequency does a stationary listener hear the sound as the plane approaches? Use 340 m/s for the speed of the sound and answer in Hz.
11. ### physics

An airplane traveling at v = 152 m/s emits a sound of frequency 1850 Hz. At what frequency does a stationary listener hear the sound as the plane approaches? Use 340 m/s for the speed of the sound and answer in Hz.
12. ### Physics

Question about doppler effect: How do you solve when it gives you percentage value? (Q 1) How do you calculate for doppler effect when the listener is moving instead of the source of sound? (Q 2) Questions 1. As a racing car zooms by you, its pitch decreases by 20%. If the ...
13. ### Physics

1. A train whistle has a frequency of 1000 Hz. If the train is speeding at a velocity of 60 km/h past a stationary railroad crossing attendant, what is the apparent frequency a) as the train approaches him, b) as it moves away from him? Assume speed of sound to be 350 m/s. 2. ...
14. ### physics

Party hearing. As the number of people at a party increases, you must raise your voice for a listener to hear you against the background noise of the other partygoers. However, once you reach the level of yelling, the only way you can be heard is if you move closer to your ...
15. ### physics

Party hearing. As the number of people at a party increases, you must raise your voice for a listener to hear you against the background noise of the other partygoers. However, once you reach the level of yelling, the only way you can be heard is if you move closer to your ...
16. ### Physics

Three sources of sound are distributed along a line, as shown in the figure. v is the speed of sound. Source A is at rest, and it emits sound waves with a frequency of 480 Hz. Source B is traveling at v/5 to the right, and it emits sound waves with a frequency of 960 Hz. ...
17. ### physics

The siren on an ambulance is emitting a sound whose frequency is 2421 Hz. The speed of sound is 343 m/s. (a) If the ambulance is stationary and you (the "observer") are sitting in a parked car, what are the wavelength and the frequency of the sound you hear? (b) Suppose that ...
18. ### phy

Doppler ultrasound is used to measure the speed of blood flow. If the speed of the red blood cells is v, the speed of sound in blood is u, the ultrasound source emits waves of frequency f, and we assume that the blood cells are moving directly toward the ultrasound source, ...
19. ### physics

a source of sound id traveling towards a stationary observer .The frequency of sound is heard by the observer is 25% more that the actual frequency.If the speed of sound is v,that of the source is options: 1.v/4 2.v/5
20. ### physics

A stationary motion detector sends sound waves of frequency 0.0953 MHz toward a truck approaching at a speed of 42.6 m/s. What is the frequency of the waves reflected back to the detector? (Take the speed of sound to be 343 m/s.)
21. ### physics

A stationary speaker is emitting a sound of frequency 1330 Hz. The air has a temperature of ^oF. Taking right to be positive, a person is moving toward the source (to the left) at 8.2 \frac{m}{s}. The person will hear a frequency of ... f =
22. ### PHY1015S

A policeman in a stationary car measures the speed of approaching cars by means of an ultrasonic device that emits a sound with a frequency of 41.2 kHz. A car is approaching him at a speed of 33.0 m/s. The wave is reflected by the car and interferes with the emitted sound ...
23. ### Physics

Two Train whistles, A and B each have a frequency of 408Hz. A is stationary and B is moving toward the right (away from A) at a speed of 35.0m/s. A listener is between the two whistles and is moving toward the right at a speed of 15.0m/s. What is the frequency from A and B as ...

A sound of 7 kHz frequency is well within the normal hearing range of most people. True. False. << 2. Sound is a transverse compression wave. True. False.<< 3. The decibel level of a sound can have a negative value. True.<< False. 4. The Doppler effect occurs...
25. ### DrBob222

As a sound source moves away from a stationary observer, the number of waves will. decrease
26. ### physics

You are riding your bicycle directly away from a stationary source of sound and hear a frequency that is 2.5% lower than the emitted frequency. The speed of sound at the temperature that day is 339 m/s. What is your speed? f = f0(v + vo)/v. Here, vo is the unknown. f = fo*.985...
27. ### physics

In this equation, vd is the speed of the detector, and vs is the speed of the source. Also, fs is the frequency of the source, and fd is the frequency of the detector. If the detector moves toward the source, vd is positive. If the source moves toward the detector, vs is ...
28. ### physic

Which of the following statements incorrectly describes a scenario where the source of the sound waves and the person hearing the sound are remaining stationary?
29. ### physic

Which of the following statements incorrectly describes a scenario where the source of the sound waves and the person hearing the sound are remaining stationary?
30. ### Physics - sound waves

I listed the questions with my answers. Are the answers correct? Thanks. A railroad locomotive is a rest with its whistle shrieking, and then it starts moving toward you. a.) Does the frequency that you hear increase, decrease, or stay the same? The frequency of the waves ...
31. ### Waves-Science

I had a couple of questions on the topic of Waves-Sound and Light. 1. What is the source of all waves? *Vibration* 2. In one word, what is it that moves from source to receiver in a wave motion? *Energy* 3. Does the medium in which a wave travels move with the wave? *No* 4. ...
32. ### Vibration and Waves

1. A girl on a playground swing makes a complete to-and-fro swing each 2 seconds. The frequency of swing is 1. (0.5 hertz) 2. (1hertz) (ANSWER) 3. (2 hertz) And the period is (FROM THE QUESTION BEFORE) 1. (0.5 seconds) (ANSWER) 2. (1 second) 3. (2 seconds) 2. The period of a ...
33. ### physics

What frequency would a listener hear if a train moves away from the listener at 180 km/hr? The frequency of the horn is 3500 Hz, and the air temperature is 19.0 degrees Celsius. Show work, and include 3 significant figures.
34. ### Physics

Two ships in a heavy fog are blowing their horns, both of which produce sound with a frequency of 165.0 Hz One ship is at rest; the other moves on a straight line that passes through the one at rest. If people on the stationary ship hear a beat frequency of 3.5 Hz, what is the...
35. ### physics

An audio speaker at a concert emits sound uniformly in all directions at a rate of 100 W. (i) Calculate the sound intensity experienced by a listener at a distance of 8 m from the speaker. The listener moves back from the speaker to protect her hearing. (ii) At what distance ...
36. ### physics

1.calculate th speed of waves in water that are 0.4m apart and have a frequency of 2hz? 2. sound waves travel at approximately 340m/s what is the wavelength of a sound with a frequency of 20Hz? what is the wavelength of a sound with a frequency of 20 kHz? 3.a bat flying in a ...
37. ### phys

An observer detects an apparent frequency of 505 hz coming from a 500 hz source. Which is true? a. the observer is moving due east, away from the stationary source b. the source is moving due west, away from the stationary observer c. the souce and the observer are moving away...
38. ### physical

You are traveling in a car toward a hill at a speed of 42.1 mph. The car's horn emits sound waves of frequency 251 Hz, which move with a speed of 343 m/s. a) Determine the frequency with which the waves strike the hill. b) What is the frequency of the reflected sound waves you...
39. ### physics

An observer detects an apparent frequency of 505 hz coming from a 500 hz source. Which is true? a. the observer is moving due east, away from the stationary source b. the source is moving due west, away from the stationary observer c. the souce and the observer are moving away...
40. ### physics

You are traveling in a car toward a hill at a speed of 40.8 mph. The car's horn emits sound waves of frequency 243 Hz, which move with a speed of 340 m/s.The frequency with which the waves strike the hill is 254.7Hz and the frequency of the reflected sound waves you hear 271.2...
41. ### Intergarted Science

I had a couple of questions on the topic of Waves-Sound and Light. 1. What is the source of all waves? *Vibration* 2. In one word, what is it that moves from source to receiver in a wave motion? *Energy* 3. Does the medium in which a wave travels move with the wave? *No* 4. ...
42. ### Science

1. A girl on a playground swing makes a complete to-and-fro swing each 2 seconds. The frequency of swing is 1. (0.5 hertz) 2. (1hertz) (ANSWER) 3. (2 hertz) And the period is (FROM THE QUESTION BEFORE) 1. (0.5 seconds) (ANSWER) 2. (1 second) 3. (2 seconds) 2. The period of a ...
43. ### Physics

The distance between a loudspeaker and the left ear of a listener is 2.19 m. (a) Calculate the time required for sound to travel this distance taking the speed of sound to be 343 m/s. (b) Assuming that the sound frequency is 525 Hz, how many wavelengths of sound are contained ...
44. ### Physics

This time I have two questions: #1.A recording engineer works in a soundproofed room that is 49.7 dB quieter than the outside. If the sound intensity in the room is 2.66 x 10-10 W/m2, what is the intensity outside? #2.A listener increases his distance from a sound source by a ...
45. ### Physics

Two eagles fly directly toward one another, the first at 13 m/s and the second at 21 m/s. Both screech, the first emitting a frequency of 3200 Hz and the second, a frequency of 3800 Hz. What frequencies do they hear if the speed of sound is 345 m/s? (Tip: keep 4 significant ...
46. ### Physics

A student has a small battery-powered alarm buzzer. The student throws the buzzer toward a stationary wall (possibly due to frustration following a physics midterm examination). The buzzer emits sound with a frequency of 74 Hz, and the wall reflects the sound. If the buzzer is...
47. ### Maths

Mathew is attending a very loud concert by the discarded. To avoid permanent ear damage he decides to move farther from the stage. Sound intensity is given by the formula I=k/d*d where k is the constant and d is the distance in metres from the listener to the source of the ...
48. ### physics

An acoustic burglar alarm consists of a source emitting waves of frequency 28.0 kHz. What is the beat frequency between the source waves and the waves reflected from an intruder walking at an average speed of 0.095 m/s directly away from the alarm?
49. ### Doppler Effect

Doppler Effect a flying bat emits squeaks at a frequency of 85 khz if a stationary observer picks up the frequency of the squeaks as 80 khz is the bat moving towards or away from the listener ? determine the speed at which the bat is flying.
50. ### physics, doppler effect

"A source of sound of frequency f0 moves horizontally at constant speed u in the x direction at a distance h above the ground. An observer is situated on the ground at the point x=0 (the source passes over this point at t=0). Show that the signal received at any time Tr at the...

You are traveling in a car toward a hill at a speed of 40.8 mph. The car's horn emits sound waves of frequency 243 Hz, which move with a speed of 340 m/s.The frequency with which the waves strike the hill is 254.7Hz and the frequency of the reflected sound waves you hear 271.2...

You are traveling in a car toward a hill at a speed of 40.8 mph. The car's horn emits sound waves of frequency 243 Hz, which move with a speed of 340 m/s.The frequency with which the waves strike the hill is 254.7Hz and the frequency of the reflected sound waves you hear 271.2...
53. ### physic

A source of sound emits waves at a frequency 650 Hz. An observer is located at a distance 190 m from the source. Use m/s for the speed of sound. (a) Assume completely still air. How many wavefronts (full waves) are there between the source and the observer? unanswered (b) If ...
54. ### Physics

A source passing a stationary observer is emitting a frequency of 560 Hz. If the speed of sound is 345 m/s, what must speed of the source be if the frequency speed is 480 hz? Here's what I've tried... Fo=480 Hz FObs = 480 + 560 VSource = ?(x) Vsound = 345 m/s I try to ...
55. ### physics - doppler effect

Two identical tuning forks can oscillate at 329.6 Hz. A person is located somewhere on the line between them. The speed of sound in the air is 343 m/s. Calculate the beat frequency as measured by this individual under the following conditions. (a) the listener is standing ...
56. ### Physics

I listed the questions with my answers. Are the answers correct? Thanks. A railroad locomotive is a rest with its whistle shrieking, and then it starts moving toward you. a.) Does the frequency that you hear increase, decrease, or stay the same? The frequency of the waves ...
57. ### physics

A siren mounted on the roof of a firehouse emits sound at a frequency of 900 Hz. A steady wind is blowing with a speed of 15 m/s. Take the speed of sound in calm air to be 343 m/s. (c) Firefighters are approaching the siren from various directions at 15.0 m/s. What frequency ...
58. ### PHYSICS

A 50cm long hollow glass cylinder is open at both ends and is suspended in air. A source o sound that produces a pure frequency is placed close to one end of the tube. The frequency of the sound is slowly increased from a very low value. The tube is first observed to resonate ...
59. ### physics

You are moving at 120 km/h toward a stationary train. The train blows its 400-Hz whistle. Take the speed of sound to be 340 m/s. What frequency do you hear?

A source emits sound uniformly in all directions. There are no reflections of the sound. At a distance of 12 m from the source, the intensity of the sound is 1.7 × 10-3 W/m2. What is the total sound power P emitted by the source? Would I do 1.7e^-3 (12) ?
61. ### Physics

Two loudspeakers are mounted on a merry-go-round whose radius is 9.68 m. When stationary, the speakers both play a tone whose frequency is 132 Hz. As the drawing illustrates, they are situated at opposite ends of a diameter. The speed of sound is 343.00 m/s, and the merry-go-...
62. ### Physics

A source produces 2000 sound waves in 4 seconds. The distance between two consecutive compressions is 55cm. Find the frequency, wavelength and speed of sound wave
63. ### Math

You are attending a loud concert. To avoid ear damage, you decide to move father from the stage. Sound intensity is given by the formula I= k/d2, where k is the constant and d is the distance in meters form the listener to the source of the sound. Determine the expression for ...
64. ### physics(URGENT!!!!!)

A source of sound emits waves at a frequency f= 650 Hz. An observer is located at a distance d= 170 m from the source. Use u=340 m/s for the speed of sound. (a) Assume completely still air. How many wavefronts (full waves) N are there between the source and the observer? N= ...
65. ### Physics

Directly below on the floor is a stationary 428-Hz source of sound. The microphone vibrates up and down in simple harmonic motion with a period of 2.3 s. The difference between the maximum and minimum sound frequencies detected by the microphone is 2.2 Hz. Ignoring any ...
66. ### physics

Which principle can be applied to explain what happens to the pitch of a sound as the source comes closer and close,pass the listener and away?

Here's the question: You are attending a very loud concert. To avoid permanent ear damage, you decide to move farther from the stage. Sound intensity is given by the formula: I = k/d squared K= constant D = distance from the listener to the source of sound. Determine an ...
68. ### physics

If the sound waves detected by the dector is the same as the frequency of the source, what can we conclude about the motion of the source and detector?
69. ### Physics

A stationary observer hears a sound with a frequency of 450 Hz from an approaching car. If the car emits the sound at a frequency of 360 Hz, what would be the speed of the car? (Speed of sound 340 m/s)
70. ### physics

An observer rides with a moving sound source directly toward a large vertical wall. The vehicle has a constant speed of 10m/s and the source has a frequency of 150Hz. What beat frequency is heard by the observer as a result of the combination of the direct and reflected sounds?
71. ### physics

1. A sound is made by a speaker, which then radiates in all directions. The sound wave is described by A(r) sin(2r - 600t) where the distances are in meters, and the time in seconds. The A(r) just indicates that the amplitude has some distance dependence--it decreases smoothly...
72. ### physics

A train at rest emits a sound at a frequency of 1089 Hz. An observer in a car travels away from the sound source at a speed of 30.7 m/s. What is the frequency heard by the observer? Assume the speed of sound in air to be 343 m/s.
73. ### physics

the distance between a loudspeaker and the left ear of a listener is 2.70 m a) calculate the time required for sound to travel this distance if the air temperature is 20oC. b) assuming that the sound frequency is 523 Hz, how many wavelengths of sound are contained in this ...
74. ### Physics _ College

A 50 cm long hollow glass cylinder is open at both ends and is suspended in air. A source of sounds that produces a pure frequency is placed close to one end of the tube. The frequency is placed close to one end of the tube. The frequency of the sound source is slowly ...
75. ### physics

From a vantage point very close to the track at a stock car race, you hear the sound emitted by a moving car. You detect a frequency that is 0.86 times as small as that emitted by the car when it is stationary. The speed of sound is 343 m/s. what is the speed of the car?
76. ### Science (physics)

You watch a distant woman driving nails into her front porch at a regular rate of 1 stroke per second. You hear the sound of the blows exactly synchronized with the blows you see. And then you hear two more blows after you see her stop hammering. How far away is she? It takes ...
77. ### Physics

A microphone is attached to a spring that is suspended from the ceiling, as the drawing indicates. Directly below on the floor is a stationary 624-Hz source of sound. The microphone vibrates up and down in simple harmonic motion with a period of 2.31 s. The difference between ...
78. ### PHYSICS

A bat flies toward a wall at a speed of 3.5 m/s. As it flies, the bat emits an ultrasonic sound wave with frequency 30.5 kHz. What frequency does the bat hear in the reflected wave? kHz
79. ### Physics 20

A 2.50-kg Pendulum is attatched to a string 11.4m stringis pulled aside until it is.386m above its lowest position and released. The pendulum is designed to emit sound waves at a frequency of 440 Hz; However, as it swings toward and away from an observer, the frequency appears...
80. ### Physics

Which of the followings is correct for waves? a. One wave can cancel another wave so that no amplitude remains at certain points. b. While you are at rest, a car moves toward you while it is making noise. The speed of this sound wave is greater than when the car is stationary...
81. ### PHYSICS

Original Q: If you pour liquid into a tall, narrow glass, you may hear sound with a steadily rising pitch. What is the source of the sound? And why does the pitch rise as the glass fills? Additional question from me: What does it mean by the source of the sound? like the ...
82. ### Physics

Two identical tuning forks have frequencies of 512 Hz. If one is held by a listener while the other approaches at a speed of 7.2 m/s, what does the listener hear?
83. ### physics

to an observer the pitch of the stationary source of the sound appears to be reduced by 20% if speed of sound is 340m/s then sped and direction of 5he observer is options 1.68 m/s away from the observer 2.96 m/s away from the observer
84. ### physics

How fast should a car move toward you for the car's horn to sound 2.88% higher in frequency than when the car is stationary? The speed of sound is 343 m/s. A)42.5 Hz B)54.5 Hz C)61.8 Hz D)65.4 Hz v=16 fs=583 vs=343 (16+0)/16 Im not even gonna post the rest because quite ...

A source emits sound uniformly in all directions. There are no reflections of the sound. At a distance r1 from the source the sound is 6.5 dB louder than it is at a distance r2 from the source. What is the ratio r1/r2?
86. ### Math/Physics

Two identical tuning forks have frequencies of 512 Hz. If one is held by a listener while the other approaches at a speed of 7.2 m/s, what does the listener hear?
87. ### physics

1. A whistle you use to call your hunting dog has a frequency of 21 kHz, but your dog is ignoring it. You suspect the whistle may not be working, but you can't hear sounds above 20 kHz. To test it, you ask a friend to blow the whistle and hop on their moped. In which direction...
88. ### physics

An electronic point source emits sound isotropically at a frequency of 3000 Hz and a power of 34 watts. A small microphone has an area of 0.75 cm2 and is located 158 meters from the point source. a) What is the sound intensity at the microphone ? To find intensity i tried I=...
89. ### Physics Sound Waves

A fire truck emitting a 450 Hz signal passes by a stationary detector. The difference in frequency measured by the detector is 58 Hz. If the speed of sound is 345 m/s, how fast is the fire truck moving? The answer should be 22 m/s but I don't even know where to start. Could ...
90. ### physics

Suppose that the range of output frequencies is from 47.4 Hz to 14.8 kHz for a pipe organ. Take 343 m/s for the speed of sound. (a) What is the length (in units of m) of the longest pipe open at both ends and producing sound at its fundamental frequency? (b) What is the length...
91. ### Physics

train moving with speed 72 km h−1 emits a whistle of frequency 600 Hz. A person is standing stationary on the platform. Calculate the frequency heard by the person if the train (i) approaches and (ii) recedes away from the listener.
92. ### physics

A train moving with speed 72 km h−1 emits a whistle of frequency 600 Hz. A person is standing stationary on the platform. Calculate the frequency heard by the person if the train (i) approaches and (ii) recedes away from the listener.
93. ### Physics

A stationary whistle emits a sound of 188 Hz. If passengers in a car hear the whistle with a frequency of 198 Hz, how fast was the car moving? Use 340 m/s for the sound velocity
94. ### DrBob222

A boy is blowing a whistle of frequency 536 Hz and walking toward a wall with a speed of 1.64 m/s. What frequency of the reflected sound will the boy hear if the speed of sound is 343 m/s? 532 Hz
95. ### physics

A boy is blowing a whistle of frequency 536 Hz and walking toward a wall with a speed of 1.64 m/s. What frequency of the reflected sound will the boy hear if the speed of sound is 343 m/s?
96. ### Physics help - Waves and Sound Questions

1) A 1.50-m long gas column that is open at one end and closed at the other has a fundamental resonant frequency 80.0 Hz. What is the sound speed in this gas? a) 120 m/s b) 30.0 m/s c) 480 m/s d) 213 m/s e) 53.3 m/s 2) You drop a stone down a well. You hear the splash 2.23 s ...
97. ### physics

Dolphins can hear ultrasound with frequencies up to 280 kHz. What is the speed of sound in water if the wavelength of ultrasound with a frequency of 2.80 × 10^5 Hz is 0.510 cm? How long would it take this sound wave to travel to a dolphin 3.00 km away?
98. ### DrBob222

How fast should a car move toward you for the car's horn to sound 2.88% higher in frequency than when the car is stationary? The speed of sound is 343 m/s. I don't know what equation to use. I think I'm suppose to use this: fs(v-vd/v-vs) I know I got it wrong I got 11.8 m/s
99. ### science

A sound source of frequency 170Hz is placed near a wall. A man walking from the source towards the wall. Find that there is a periodic rise and fall of sound intensity?
100. ### physics

A source of sound (1000 Hz) emits uniformly in all directions. An observer 3.19 m from the source measures a sound level of 39.2 dB. Calculate the average power output of the source.