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Ch 15: Mechanical Waves
Young & Freedman Calc - University Physics 14th Edition
Young & Freedman Calc14th EditionUniversity PhysicsISBN: 9780321973610당신이 사용하는 게 아니라요?교과서 변경
15장, 문제 44

One string of a certain musical instrument is 75.0 cm long and has a mass of 8.75 g. It is being played in a room where the speed of sound is 344 m/s. (a) To what tension must you adjust the string so that, when vibrating in its second overtone, it produces sound of wavelength 0.765 m? (Assume that the break-ing stress of the wire is very large and isn't exceeded.) (b) What frequency sound does this string produce in its fundamental mode of vibration?

검증된 단계별 안내
1
Convert the mass of the string from grams to kilograms by dividing by 1000, since 1 g = 0.001 kg.
Calculate the linear mass density (μ) of the string using the formula: μ = mass/length. Ensure the length is in meters.
For part (a), use the relationship between the speed of a wave on a string (v), tension (T), and linear mass density (μ): v = sqrt(T/μ).
In the second overtone, the string vibrates in its third harmonic, meaning the wavelength of the wave on the string is 2/3 of the string's length. Use this to find the wave speed on the string: v = frequency * wavelength.
For part (b), the fundamental frequency (first harmonic) of the string is given by: f1 = v / (2 * length of the string). Use the wave speed found in part (a) to calculate this frequency.

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이 영상 해법은 위 문제에 도움이 된다고 튜터들이 추천한 것입니다.
영상 길이:
10m
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주요 개념

질문에 올바르게 답하기 위해 반드시 이해해야 하는 핵심 개념들은 다음과 같습니다.

Wave Speed on a String

The speed of a wave on a string is determined by the tension in the string and its linear density. It is given by the formula v = sqrt(T/μ), where T is the tension and μ is the linear density (mass per unit length). Understanding this relationship is crucial for calculating the tension needed for a specific wave speed.
추천 영상:
04:39
Energy & Power of Waves on Strings

Overtones and Harmonics

Overtones are higher frequency modes of vibration that occur at integer multiples of the fundamental frequency. The second overtone corresponds to the third harmonic, where the string vibrates in three segments. This concept helps in determining the wavelength and frequency of the sound produced by the string.
추천 영상:
07:52
Simple Harmonic Motion of Pendulums

Fundamental Frequency

The fundamental frequency is the lowest frequency at which a string vibrates, corresponding to the first harmonic. It is determined by the length, tension, and mass of the string. Calculating the fundamental frequency involves understanding the relationship between these factors and the wave speed on the string.
추천 영상:
05:08
Circumference, Period, and Frequency in UCM
관련 실천
교과서 질문

A horizontal string tied at both ends is vibrating in its fundamental mode. The traveling waves have speed vv, frequency ff, amplitude AA, and wavelength λ\(\lambda\). Calculate the maximum transverse velocity and maximum transverse acceleration of points located at (i) x=λ/2x = λ/2, (ii) x=λ/4x = λ/4, and (iii) x=λ/8x = λ/8, from the left-hand end of the string.

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교과서 질문

The wave function of a standing wave is y(x,t)=4.44 mmsin[(32.5 rad/m)x]sin[(754rad/s)t]y(x,t)=4.44\(\text{ mm}\]\sin\)[(32.5\(\text{ rad/m}\))x]\(\sin\)[(754\(\text{rad/s}\))t]. For the two traveling waves that make up this standing wave, find the frequency.

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교과서 질문

A horizontal string tied at both ends is vibrating in its fundamental mode. The traveling waves have speed vv, frequency ff, amplitude AA, and wavelength λ\(\lambda\). How much time does it take the string to go from its largest upward displacement to its largest downward displacement at the points located at (i) x=λ/2x = λ/2, (ii) x=λ/4x = λ/4, and (iii) x=λ/8x = λ/8, from the left-hand end of the string.

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교과서 질문

The wave function of a standing wave is y(x,t)=4.44 mmsin[(32.5 rad/m)x]sin[(754rad/s)t]y(x,t)=4.44\(\text{ mm}\]\sin\)[(32.5\(\text{ rad/m}\))x]\(\sin\)[(754\(\text{rad/s}\))t]. For the two traveling waves that make up this standing wave, find the wavelength.

2060
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교과서 질문

A horizontal string tied at both ends is vibrating in its fundamental mode. The traveling waves have speed vv, frequency ff, amplitude AA, and wavelength λ\(\lambda\). What is the amplitude of the motion at the points located at (i) x=λ/2x = λ/2, (ii) x=λ/4x = λ/4, and (iii) x=λ/8x = λ/8, from the left-hand end of the string?

1751
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교과서 질문

The wave function of a standing wave is y(x,t)=4.44 mmsin[(32.5 rad/m)x]sin[(754rad/s)t]y(x,t)=4.44\(\text{ mm}\]\sin\)[(32.5\(\text{ rad/m}\))x]\(\sin\)[(754\(\text{rad/s}\))t]. For the two traveling waves that make up this standing wave, find the wave speed.

1497
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