Exam 21: Mechanical Waves

One of the harmonics of a column of air in a tube that is open at one end and closed at the other has a frequency of 448 Hz,and the next higher harmonic has a frequency of 576 Hz.How long is the tube? The speed of sound in air is 343 m/s.

An organ pipe of length L that is open at one end resonates in its third harmonic with a wavelength of 2L/3.Is the other end of the pipe closed or open?

A 10-gram wire that is 6.0 m long is under tension.When a transverse wave of frequency 280 Hz travels along the wire,its wavelength is 0.60 m,and its amplitude is 8.4 mm.How much time does it take for a crest of the transverse wave to travel the length of the wire?

A siren emitting sound of frequency 1000 Hz approaches a stationary observer at one-half the speed of sound.The observer hears a frequency of

The speed of propagation of a transverse wave on a 2.0-m long string fixed at both ends is 200 m/s.Which one of the following is not a resonant frequency of this string?

Two steel wires are stretched with the same tension.The first wire has a diameter of 0.610 mm and the second wire has a diameter of 0.910 mm.If the speed of waves traveling along the first wire is 54.0 m/s,what is the speed of waves traveling along the second wire?

A guitar string 0.65 m long has a tension of 61 N and a mass per unit length of 3.0 g/m. (a)What is the speed of waves on the string when it is plucked? (b)What is the string's fundamental frequency of vibration when plucked? (c)At what other frequencies will this string vibrate?

A rope with a total mass of 25.0 kg is tied to a tree on one side of a 125-m wide ravine.You are pulling on the other end of the rope with a force of 415 N.If you pluck the rope at your end,how long will it take the pulse to travel across the ravine to the tree?

Two loudspeakers placed 6.00 m apart are driven in phase by an audio oscillator having a frequency range from 1908 Hz to 2471 Hz.A point P is located 4.70 m from one loudspeaker and 3.60 m from the other speaker.At what frequency of the oscillator does the sound reaching point P interfere constructively? The speed of sound is 344 m/s.

Two in-phase loudspeakers are placed along a wall and are separated by a distance of 4.00 m.They emit sound with a frequency of 514 Hz.A person is standing away from the wall,in front of one of the loudspeakers.What is the closest nonzero distance from the wall the person can stand and hear constructive interference? The speed of sound in air is 343 m/s.

When a guitar is tuned to adjust it pitch,what is it that is changed?

A tsunami,an ocean wave generated by an earthquake,propagates along the open ocean at 700 km/hr and has a wavelength of 750 km.What is the frequency of the waves in such a tsunami?

Why does the intensity of waves from a small source decrease with the square of the distance from the source?

What is the intensity of a 70-dB sound? The threshold of human hearing is 1.0 × 10^-12 W/m².

Two in-phase loudspeakers are placed along a wall and are separated by a distance of 4.00 m.They emit sound with a frequency of 514 Hz.A person is standing away from the wall,in front of one of the loudspeakers.What is the closest distance from the wall the person can stand and hear no sound (destructive interference)? The speed of sound in air is 343 m/s.

Consider two pipes of the same length: one pipe is open at both ends and the other pipe is closed on one end but open at the other end.If the fundamental frequency of the totally open pipe is 300 Hz,what is the fundamental frequency of the other pipe?

Two pure tones are sounded together and a particular beat frequency is heard.What happens to the beat frequency if the frequency of one of the tones is increased?

In a resonating pipe that is open at one end and closed at the other end,there

What is the length of the shortest pipe closed on one end and open at the other end that will have a fundamental frequency of 0.060 kHz on a day when the speed of sound is 340 m/s?

A 2.31-kg rope is stretched between supports that are 10.4 m apart,and has a tension in it of 49.2 N.If one end of the rope is slightly tweaked,how long will it take for the resulting disturbance to reach the other end?