/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none} Q47E Two train whistles, A and B, eac... [FREE SOLUTION] | 91影视

91影视

Log out

Learning Materials

Features

Discover

Chapter 2: Q47E (page 541)

Two train whistles, A and B, each have a frequency of 393Hz. A is stationary and B is moving toward the right (away from A) at a speed of 35m/s. A listener is between the two whistles and is moving toward the right with a speed of 15m/s. No wind is blowing. (a) What is the frequency from A as heard by the listener? (b) What is the frequency from B as heard by the listener? (c) What is the beat frequency detected by the listener?

Short Answer

Expert verified

a) 375Hz

b) 370.75Hz

c) 4 Hz

Step by step solution

01

Doppler’s effect

The Doppler鈥檚 effect is given by the formula, fL=v+vLv+sfs, where

  • fLis the frequency observed by the listener.
  • vis the speed of sound.
  • vLis the speed of the listener.
  • vsis the speed of the source of sound.
  • vsis the frequency of the source of sound.
02

Calculate frequency when the listener is moving away from the source

fL=v+vLv+vSfSfL=344-15344+0脳392fL=375Hz

03

Calculate frequency when listener is moving towards the source and source is moving away from the listener

fL=v+vLv+vSfSfL=344+15344+35脳392fL=370.75Hz

04

Calculate beat

beat=|f1-f2|beat=|375-370.75|beat=4Hz

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Over 30 million students worldwide already upgrade their learning with 91影视!

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

Interference of Rectangular Pulses. Figure E15.35 shows two rectangular wave pulses on a stretched string traveling toward each other. Each pulse is traveling with a speed of \(1.00\;{{{\rm{mm}}} \mathord{\left/ {\vphantom {{{\rm{mm}}} {\rm{s}}}} \right. \\} {\rm{s}}}\) and has the height and width shown in the figure. If the leading edges of the pulses are \(8.00\;{\rm{mm}}\) apart at \(t = 0\), sketch the shape of the string at \(t = 4.00\;{\rm{s}}\), \(t = 6.00\;{\rm{s}}\), and \(t = 10.0\;{\rm{s}}\).

A thin, 75.0cm wire has a mass of 16.5g. One end is tied to a nail, and the other end is attached to a screw that can be adjusted to vary the tension in the wire. (a) To what tension (in newtons) must you adjust the screw so that a transverse wave of wavelength 3.33 cm makes 625 vibrations per second? (b) How fast would this wave travel?

A railroad train is traveling at 30.0 m/s in still air. The frequency of the note emitted by the train whistle is 352 Hz. What frequency is heard by a passenger on a train moving in the opposite direction to the first at 18.0 m/s and (a) approaching the first and (b) receding from the first?

Two loudspeakers, A and B (see Fig. E16.35), are driven by the same amplifier and emit sinusoidal waves in phase. Speaker B is 2.00 m to the right of speaker A. The frequency of the sound waves produced by the loudspeakers is 206 Hz. Consider a point P between the speakers and along the line connecting them, a distance x to the right of A. Both speakers emit sound waves that travel directly from the speaker to point P. For what values of x will (a) destructive interference occur at P; (b) constructive interference occur at P? (c) Interference effects like those in parts (a) and (b) are almost never a factor in listening to home stereo equipment. Why not?

(a) If two sounds differ by 5.00 dB, find the ratio of the intensity of the louder sound to that of the softer one. (b) If one sound is 100 times as intense as another, by how much do they differ in sound intensity level (in decibels)? (c) If you increase the volume of your stereo so that the intensity doubles, by how much does the sound intensity level increase?
See all solutions

Recommended explanations on Physics Textbooks

Nuclear Physics

Read Explanation

Turning Points in Physics

Read Explanation

Modern Physics

Read Explanation

Further Mechanics and Thermal Physics

Read Explanation

Electromagnetism

Read Explanation

Geometrical and Physical Optics

Read Explanation
View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.