Exam 14: Waves and Sound

The intensity at a distance of 6.0 m from a source that is radiating equally in all directions is 6.0 × 10^-10 W/m².What is the intensity level in dB? The threshold of human hearing is 1.0 × 10^-12 W/m².

A string that is 2.0 meters long is fixed at both ends and tightened until the wave speed is What is the frequency of the standing wave shown in the figure?

Calculate the light intensity 1.45 m from a light bulb that radiates 100 W equally in all directions.

A 15-m rope is pulled taut with a tension of 140 N.It takes 0.545 s for a wave to propagate along the rope.What is the mass of the rope?

Two in-phase loudspeakers that emit sound with the same frequency are placed along a wall and are separated by a distance of 5.00 m.A person is standing 12.0 m away from the wall,equidistant from the loudspeakers.When the person moves 1.00 m parallel to the wall,she experiences destructive interference for the first time.What is the frequency of the sound? The speed of sound in air is 343 m/s.

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

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 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. )

If the intensity level of one trombone is 70 dB,calculate a reasonable estimate for the intensity level of 76 trombones all playing simultaneously in the same place?

Transverse waves travel at In a string that is subjected to a tension of If the string is Long,what is its mass?

You double your distance from a sound source that is radiating equally in all directions.What happens to the intensity level of the sound? It drops by

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?

By how many decibels does the intensity level of a sound increase when you triple the intensity of a source of sound?

A crane lifts a 2500-kg beam at a steady rate of 15 cm/s using a steel cable whose mass per unit length is 0.65 kg/m.What is the speed of transverse waves on this cable?

The sound from the whistle of a truck moving at 17.0 m/s toward a cliff reflects from the cliff and is heard by the driver of the truck.When it is parked at the side of the road,the whistle from the truck produces sound of frequency 2.267 kHz.As observed by the driver of the truck,what is the change in frequency the sound from the whistle due to the reflection? The speed of sound is 343 m/s.

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

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

A string of length L is under tension,and the speed of a wave in the string is v.What will be the speed of a wave in the string if the length is increased to 2L but with no change in the mass or tension?

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 some distance apart.They emit sound with a frequency of 536 Hz.A microphone is moved between the speakers along the line joining the two speakers with a constant speed of 1.60 m/s.What beat frequency is observed? The speed of sound in air is 343 m/s.