Warning: foreach() argument must be of type array|object, bool given in /var/www/html/web/app/themes/studypress-core-theme/template-parts/header/mobile-offcanvas.php on line 20

BIO For a person with normal hearing, the faintest sound that can be heard at a frequency of 400 Hz has a pressure amplitude of about 6.0×10-5Pa. Calculate the (a) intensity; (b) sound intensity level; (c) displacement amplitude of this sound wave at 20°C.

Short Answer

Expert verified

A) I=4.36×10-12W/m2 b) β=6.4dB c) A=5.8×10-11m

Step by step solution

01

Concept of the intensity of the sound wave in terms of the pressure amplitude

Formula isI=vp2max2D isthe relation that describes the intensity of the sound wave in terms of the pressure amplitude

02

Calculate the intensity of he sounds

Substitute the values in the equationI=vp2max2Dwe get,

I=344×6×10-522×1.42×105=4.36×10-12W/m2

The relation that describes the intensity level of a sound wave isβ=10logll0 .Substitute the values in the above equation we get,

β=10log4.36×10-12W/m210-12W/m2=6.4dB

Therefore, the intensity of the sound is 6.4dB

03

Step 3 The relation between the displacement amplitude and the pressure amplitude

The equation is A=PmaxkB

We know that the Bulk modulus for the air is B=1.42×105Paand the pressure amplitude is 6×10-5Pabut in order to make use of equation (3) we need to determine k, where k can be represented as follows

k=2πλλ=vf=344400=0.86mk=2π0.86m=7.3rad/mA=6×10-5Pa7.3rad/m×1.42×105Pa=5.8×10-11m

Therefore, the pressure amplitude is5.8×10-11m

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 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

A swimming duck paddles the water with its feet once every 1.6 s, producing surface waves with this period. The duck is moving at constant speed in a pond where the speed of surface waves is 0.32 m/s, and the crests of the waves ahead of the duck are spaced 0.12 m apart. (a) What is the duck’s speed? (b) How far apart are the crests behind the duck?

Two identical loudspeakers are located at points A and B, 2.00 m apart. The loudspeakers are driven by the same amplifier and produce sound waves with a frequency of 784 Hz. Take the speed of sound in air to be 344 m/s. A small microphone is moved out from point Balong a line perpendicular to the line connecting Aand B(line BC in Fig. P16.65). (a) At what distances from Bwill there be destructiveinterference? (b) At what distances from Bwill there be constructiveinterference? (c) If the frequency is made low enough, there will be no positions along the line BCat which destructive interference occurs. How low must the frequency be for this to be the case?

The hero of a western movie listens for an oncoming train by putting his ear to the track. Why does this method give an earlier warning of the approach of a train than just listening in the usual way?

Two guitarists attempt to play the same note of wavelength 64.8cm at the same time, but one of the instruments is slightly out of tune and plays a note of wavelength 65.2cm instead. What is the frequency of the beats these musicians hear when they play together?

An organ pipe has two successive harmonics with frequencies 1372 and 1764 Hz. (a) Is this an open or a stopped pipe? Explain. (b) What two harmonics are these? (c) What is the length of the pipe?

See all solutions

Recommended explanations on Physics Textbooks

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