Exam 16: Traveling Waves

A stationary siren emits sound of frequency 1000 Hz and wavelength 0.343 m.An observer who is moving toward the siren will measure a frequency f and wavelength λ for this sound such that

A plane flies toward a stationary siren at 1/4 the speed of sound.Then the plane stands still on the ground and the siren is driven toward it at 1/4 the speed of sound.In both cases,a person sitting in the plane will hear the same frequency of sound from the siren.

Two people are talking at a distance of 3.0 m from where you are and you measure the sound intensity as 1.1 × 10^-7 W/m².Another student is 4.0 m away from the talkers.What sound intensity does the other student measure? Assume that the sound spreads out uniformly and undergoes no significant reflections or absorption.

A factory siren indicating the end of a shift has a frequency of 90.0 Hz.The speed of sound is 343 m/s. (a)What frequency is perceived by the occupant of a car traveling towards the factory at 25.0 m/s? (b)What frequency is perceived by the occupant of a car traveling away from the factory at 30.0 m/s?

Four traveling waves are described by the following equations,where all quantities are measured in SI units and y represents the displacement. I: y = 0.12 cos(3x + 2t) II: y = 0.15 sin(6x - 3t) III: y = 0.23 cos(3x + 6t) IV: y = -0.29 sin(1.5x - t) Which of these waves have the same speed?

Waves travel along a 100-m length of string which has a mass of 55 g and is held taut with a tension of 75 N.What is the speed of the waves?

The howler monkey is the loudest land animal and,under some circumstances,can be heard up to a distance of 8.9 km.Assume the acoustic output of a howler to be uniform in all directions and that the threshold of hearing is 1.0 × 10^-12 W/m².A juvenile howler monkey has an acoustic output of What is the ratio of the acoustic intensity produced by the juvenile howler to the reference intensity I₀,at a distance of 210 m?

The figure shows the displacement y of a traveling wave at a given position as a function of time and the displacement of the same wave at a given time as a function of position.How fast is the wave traveling?

A transverse wave traveling along a string transports energy at a rate r.If we want to double this rate,we could

At a distance of 2.00 m from a point source of sound,the intensity level is 80.0 dB.What will be the intensity level at a distance of 4.00 m from this source? The lowest detectable intensity is 1.0 × 10^-12 W/m².

What characteristic of sound determines the "pitch" of a musical note?