UA-78309841-1

# ## Solution Search

• Abhigyan Martin Ninama
September 8, 2017
• Rohit Dewal
July 8, 2017
• Ajay kumar
January 14, 2017
• September 27, 2016

## . : "Sound"

### Standing Waves: Vibrating string

Q- Figure shows the standing wave on a string, oscillating at frequency fo.

(a) How many antinodes will there be if the frequency is doubled to 2fo.

(b) If the tension in the string is increased by a factor of four, for what frequency will the string continue to oscillate as a standing wave with…

### Sound Waves: Beats

Q- A flute player hears four beats per second when she compares her note to a 523 Hz tuning fork. She can match the frequency of the tuning for by pulling out to increase length of her flute slightly. What was her initial frequency?

Solution:

### Travelling Waves on Stretched String

Q- Figure below is the snapshot graph at t = 0 of two waves approaching each other at 1.0 m/s. Draw six snapshot graphs showing the string at 1 s intervals from t = 1s to t = 6s. Solution:

### Sound: Standing Waves on Stretched String

Q- A string vibrates at its third harmonic frequency. The amplitude at a point 30 cm from one end is half the maximum amplitude. How long is the string?

Solution:

### Sound: Resonance

Q- A 1.2 m long tube is closed at one end. A stretched wire is placed near the open end. The wire is 0.330 m long and has a mass of 9.60 g. It is fixed at both ends and oscillates in its fundamental mode. By resonance it sets the air column in the tube into oscillation at the column’s fundamental fr…

### Sound: Doppler's Effect

Q- A commuter train passes a station platform at a constant speed of 40 m/s. The train horn sounded at its characteristic frequency of 320 Hz. What change in frequency is detected by a person standing on the platform as the train moves past from approaching to receding? (speed of sound in air is 340…

### Stationary Waves: Closed Organ Pipe

Q- An organ pipe is closed at one end and is 1.00 m long. Find the wavelength and frequency of the three lowest resonances which this pipe can produce. (speed of sound in air is 340 m/s)

Solution:

### Standing Waves

Q- One of the 63.5 cm long strings of an ordinary guitar is tuned to produce the not B (frequency 245 Hz) when vibrating in its fundamental mode.

(a) find the speed of the transverse wave on this string.

(b) If the tension in the string is doubled, what will be the new fundamental frequency of the…

### Sound: Intensity and Loudness

Q- A loudspeaker emits a power of 100 W and can be considered as appoint source. Find the sound intensity and sound level in dB at a distance of 10 m from the speaker. How close would you have to be to the speaker for the sound level to be at the threshold of pain (120 dB)?  (The threshold of hearin…

### Sound: Resonance

Q- A closed end organ pipe is sounded near a guitar causing one of the strings to vibrate with large amplitude. The string is 80% as long as the organ pipe. If both vibrate at their fundamental frequency, calculate the ratio of the speed of wave on the string to the speed of sound in air.

Solution…

### Sound: Intensity and Loudness

Q- When a pin of mass 0.120 g is dropped from a height of 0.80 m and 0.05% of its energy is converted into a sound pulse with a duration of 0.1 s.

(a) Estimate the range at which the dropped pin can be heard if the minimum audible intensity is 10-11 W/m2.

(b) Your result in (a) is much too larg…

### Transverse Waves: Stretched Strings

Q- A 1.5 m long rope is stretched between two supports with a tension that makes the speed of transverse waves on the rope 48 m/s. The rope is made to vibrate, what will be the wavelength an frequency of

(a) the fundamental and

(b) the fourth harmonic?

Solution:

### Transverse Waves

Q- One of the 63.5 cm long guitar wire is tuned  to produce note B (245 Hz) when vibrating in its fundamental mode.

(a) Find the speed of the transverse wave on the string.

(b) If the tension in the string is doubled, what will be the new fundamental frequency?

Solution:

### Sound Waves: Wave-front

Q- A sound source is located somewhere along the x-axis. Experiments show that the same wave front simultaneously reaches listeners at x = -6 m and x = +8.0 m.

(a) What is the x co ordinate of the source?

(b) A third listener is positioned along the positive y-axis. What is her y coordinate if the…

### Sound Waves: Interference

Q- Two in-phase loudspeakers are located at (x, y) coordinates (-2.5 m, +2.0 m) and (-2.5 m, -2.0 m). They emit identical sound waves with a 1.6 m wavelength and amplitude a. Determine the amplitude A of the sound at the five positions on the y-axis (x = 0) with the y values 0, 0.5 m, 1.0 m, 2.0 m.

### Standing waves

Q- A 1.5 m long string is stretched between two supports with a tension such that the speed of the transverse wave on the string is 48 m/s. The string is made to vibrate. Find the wavelength and frequency of

1. Fundamental note, and
2. The fourth harmonic.

### Waves

Q- Figure shows snapshot graph at t = 0 of two waves approaching each other at 1 m/s. Draw six snapshots graphs showing the string at 1 s intervals from t = 1 s to t = 6 s. Solution:

### Standing Waves

Q- A 78 cm long guitar string with a linear density of 1.0 g/m is under 225 N tension. It is plucked and vibrates at its fundamental frequency. What is the wavelength of the sound wave that reaches your ear in a 20°C room?

Solution:

### Waves

Q- Figure shows a snapshot graph of a wave traveling to the right along a string at 55 m/s. Each interval on the vertical axis corresponds to 0.5 cm. At this instant, what is the velocity of points 1, 2, and 3 on the string? Solution:

### Waves

Q- Earthquakes are essentially sound waves traveling through the earth. They are called seismic waves. Because the earth is solid, it can support both longitudinal and transverse seismic waves. These travel at different speeds. The speed of longitudinal waves, called P waves, is 8000 m/s. Transverse…

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