Skip to main content
Ch 15: Mechanical Waves
Young & Freedman Calc - University Physics 14th Edition
Young & Freedman Calc14th EditionUniversity PhysicsISBN: 9780321973610Non è quello che usi tu?Cambia libro di testo
Capitolo 15, Problema 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?

Guida verificata passo dopo passo
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.

Risposta video verificata per un problema simile:

Questa soluzione video è stata consigliata dai nostri tutor come utile per risolvere questo problema.
Durata del video:
10m

Concetti chiave

Ecco i concetti essenziali che devi comprendere per rispondere correttamente alla domanda.

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.
Video consigliato:
Percorso guidato
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.
Video consigliato:
Percorso guidato
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.
Video consigliato:
Percorso guidato
05:08
Circumference, Period, and Frequency in UCM
Pratica correlata
Domanda del libro di testo

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.

1333
views
Domanda del libro di testo

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.

1495
views
Domanda del libro di testo

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.

1754
views
Domanda del libro di testo

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
views
Domanda del libro di testo

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
views
Domanda del libro di testo

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
views