第17章音

If a wind instrument, such as a tuba, has a fundamental frequency of 32.0 Hz, what are its first three overtones? It is closed at one end. (The overtones of a real tuba are more complex than this example, because it is a tapered tube.)

What are the first three overtones of a bassoon that has a fundamental frequency of 90.0 Hz? It is open at both ends. (The overtones of a real bassoon are more complex than this example, because its double reed makes it act more like a tube closed at one end.)

How long must a flute be in order to have a fundamental frequency of 262 Hz (this frequency corresponds to middle C on the evenly tempered chromatic scale) on a day when air temperature is $20.0\text{°}\text{C}$? It is open at both ends.

What length should an oboe have to produce a fundamental frequency of 110 Hz on a day when the speed of sound is 343 m/s? It is open at both ends.

(a) Find the length of an organ pipe closed at one end that produces a fundamental frequency of 256 Hz when air temperature is $18.0\text{°}\text{C}$. (b) What is its fundamental frequency at $25.0\text{°}\text{C}$?

An organ pipe $\left(L=3.00\text{m}\right)$ is closed at both ends. Compute the wavelengths and frequencies of the first three modes of resonance. Assume the speed of sound is$v=343.00\text{m/s}\text{.}$

An organ pipe $\left(L=3.00\text{m}\right)$ is closed at one end. Compute the wavelengths and frequencies of the first three modes of resonance. Assume the speed of sound is$v=343.00\text{m/s}\text{.}$

A sound wave of a frequency of 2.00 kHz is produced by a string oscillating in the $n=6$ mode. The linear mass density of the string is $\mu =0.0065\text{kg/m}$ and the length of the string is 1.50 m. What is the tension in the string?

Consider the sound created by resonating the tube shown below. The air temperature is $T_{\text{C}}=30.00\text{°}\text{C}$. What are the wavelength, wave speed, and frequency of the sound produced?

A student holds an 80.00-cm lab pole one quarter of the length from the end of the pole. The lab pole is made of aluminum. The student strikes the lab pole with a hammer. The pole resonates at the lowest possible frequency. What is that frequency?

A string on the violin has a length of 24.00 cm and a mass of 0.860 g. The fundamental frequency of the string is 1.00 kHz. (a) What is the speed of the wave on the string? (b) What is the tension in the string?

By what fraction will the frequencies produced by a wind instrument change when air temperature goes from $10.0\text{°}\text{C}$ to $30.0\text{°}\text{C}$? That is, find the ratio of the frequencies at those temperatures.