Log out Go to App
Go to App

Learning Materials

Features

Discover

Chapter 16: Q. 39 (page 452)

A loudspeaker on a tall pole broadcasts sound waves equally in all directions. What is the speaker’s power output if the sound intensity level is 90 dB at a distance of 20 m?

Short Answer

Expert verified

The power output of the speaker is5W.

Step by step solution

01

Given information

The sound intensity level of the loudspeaker is β=90dB.

Distance isr=20m.

02

Power output of the speaker

The sound level intensity of the speaker is given by β=10dBlog10II0…1.

The intensity of the sound wave is given by I=Pa…2

From (1) and (2) we get,

P=IaP=I0×10β10dB×4πr2

Substitute the given values

P=1×10-12×1090dB10dB×4π202P≈5W

Therefore, the power output of the speaker is5W.

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.

Start your free trial

Over 30 million students worldwide already upgrade their learning with Vaia!

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

The wave speed on a string under tension is 200 m/s. What is the speed if the tension is halved?

FIGURE EX16.9 is the snapshot graph at t = 0 s of a longitudinal wave. Draw the corresponding picture of the particle positions, as was done in Figure 16.9b. Let the equilibrium spacing between the particles be 1.0 cm

You are standing at x = 0 m, listening to a sound that is emitted at frequency f0. The graph of FIGURE Q16.12 shows the frequency you hear during a 4-second interval. Which of the following describes the sound source? Explain your choice.

A. It moves from left to right and passes you at t = 2 s.

B. It moves from right to left and passes you at t = 2 s.

C. It moves toward you but doesn’t reach you. It then reverses direction at t = 2 s.

D. It moves away from you until t = 2 s. It then reverses direction and moves toward you but doesn’t reach you

A sinusoidal wave travels along a stretched string. A particle on the string has a maximum speed of 2.0 m/s and a maximum acceleration of 200 m/s2. What are the frequency and amplitude of the wave?

Earthquakes are essentially sound waves—called seismic

waves—traveling through the earth. Because the earth is solid, it can support both longitudinal and transverse seismic waves. The speed of longitudinal waves, called P waves, is 8000 m/s. Transverse waves, called S waves, travel at a slower 4500 m/s. A seismograph records the two waves from a distant earthquake. If the S wave arrives 2.0 min after the P wave, how far away was the earthquake? You can assume that the waves travel in straight lines, although actual seismic waves follow more complex routes.
See all solutions

Recommended explanations on Physics Textbooks

Modern Physics

Read Explanation

Conservation of Energy and Momentum

Read Explanation

Electric Charge Field and Potential

Read Explanation

Fundamentals of Physics

Read Explanation

Linear Momentum

Read Explanation

Radiation

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.

Sign-up for free