Exam 21: Mechanical Waves

A standing wave of the third overtone is induced in a 1.2-m pipe that is open at one end and closed at the other end.The speed of sound in the pipe is 340 m/s. (a)How many antinodes are there in the standing wave pattern? (b)What is the frequency of the sound produced by the pipe in this situation?

A wave whose wavelength is 0.500 m is traveling down a 500-m long wire whose total mass is 25 kg and is under a tension of 2000 N. (a)What is the speed of the wave on the wire? (b)Find the frequency of this wave.

An organ pipe that is 1.75 m long and open at both ends produces sound of frequency 303 Hz when resonating in its second overtone.What is the speed of sound in the room?

A guitar-like stringed instrument has a string that is 16 cm long.It sounds the musical note A (440 Hz)when played without fingering.By what distance should you shorten it to play the note C (523 Hz)?

The intensity of the waves from a point source at a distance d from the source is I.At what distance from the sources is the intensity equal to 2I?

One of the harmonics of a string fixed at both ends has a frequency of 52.2 Hz and the next higher harmonic has a frequency of 60.9 Hz.What is the fundamental frequency of the string?

Consider a pipe of length L that is open at one end and closed at the other end.What are the wavelengths of the three lowest-pitch tones produced by this pipe?

What is the wavelength of the wave shown in the figure?

A crying baby emits sound with an intensity of 8.0 × 10^-8 W/m².Calculate a reasonable estimate for the intensity level from a set of quintuplets (five babies),all crying simultaneously at the same place? The lowest detectable intensity is 1.0 × 10^-12 W/m².

A string that is 0.15 m long and fixed at both ends is vibrating in its n = 5 harmonic.The sound from this string excites a pipe that is $0.82 \mathrm {~m}$ long and open at both ends into its second overtone resonance.What is the distance between a node and an adjacent antinode,in the string? The speed of sound in air is 345 m/s.

Two loudspeakers placed 6.00 m apart are driven in phase by an audio oscillator having a frequency range from 1595 Hz to 2158 Hz.A point P is located 4.70 m from one loudspeaker and 3.60 m from the other speaker.The speed of sound in the room is 344 m/s.At what frequency (or frequencies)of the oscillator does the sound reaching point P interfere destructively? (There could be more than one correct choice.)

An elephant can hear sound with a frequency of 15 Hz.What is the wavelength of this wave if the speed of sound in air is 343 m/s?

The figure shows a "snapshot" of a wave at a given instant of time.The frequency of this wave is 120 Hz.What are the (a)amplitude,(b)wavelength,and (c)speed of this wave?

A 0.13-m string,fixed at both ends and vibrating in its n = 4 harmonic,excites a pipe that is $0.88 \mathrm {~m}$ long and open at both ends,into its second overtone resonance.What is the speed of transverse waves on the string? The speed of sound in air is 345 m/s.

An organ pipe closed at one end and open at the other end has two successive harmonics with frequencies of 2170 Hz and 2790 Hz.What is the fundamental frequency of the pipe?

A pipe that is 0.92 m long and open at both ends vibrates in the second overtone with a frequency of $584 \mathrm {~Hz}$ What is the speed of sound in the air in this pipe?

In many cartoon shows,a character runs off a cliff,realizes his predicament,and lets out a scream.He continues to scream as he falls.If the physical situation is portrayed correctly,from the vantage point of an observer at the top of the cliff leaning over the edge,the pitch of the scream as he falls should be

You are moving at 120 km/h toward a stationary train.The train blows its 0.400-kHz whistle.Take the speed of sound to be 340 m/s.What frequency do you hear?

The density of aluminum is 2700 kg/m³.If transverse waves travel at $38 \mathrm {~m} / \mathrm { s }$ in an aluminum wire of diameter $4.6 \mathrm {~mm}$ what is the tension on the wire?

You drop a stone down a well that is 9.5 m deep.How long is it before you hear the splash? The speed of sound in air is 343 m/s and air resistance is negligible.