1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
andrey2020 [161]
3 years ago
11

To understand the concept of intensity; the relationship between the power of the source and the intensity of the wave; and the

dependence of intensity on distance.Since waves transfer energy from one point to another, one can define the power of a wave as the rate at which the wave transports energy. The intensity of a wave, in contrast, is the power relative to a certain surface. Consider a wave traveling across a surface perpendicular to the direction of propagation. The intensity Iof the wave is defined as the ratio of the power P of the wave to the area A of that surface:I=PA.Note that the surface may be real (physical, like an eardrum or a windowpane) or mathematical. Quite frequently, we will be interested in the intensity produced by a relatively small source at a relatively large distance. If the source emits waves uniformly in all possible directions (produces spherical waves), the formula given here makes it possible to find the intensity at a distance r from the source:I=P/4?r^2.Note that, in all parts of this problem, assume that the source generates spherical waves, so that this intensity formula is applicable.Intensity is measured in watts per square meter (W/m^2). All the information presented here is pertinent to any kind of wave. In this problem, we will be focusing on sound waves.A popular car stereo has four speakers, each rated at 60 W. In answering the following questions, assume that the speakers produce sound at their maximum power.A:Find the intensity I of the sound waves produced by one 60-Wspeaker at a distance of 1.0 m.Express your answer numerically in watts per square meter. Use two significant figures.B:Find the intensity I of the sound waves produced by one 60-Wspeaker at a distance of 1.5 m.Express your answer numerically in watts per square meter. Use two significant figures.C:Find the intensity I of the sound waves produced by four 60-Wspeakers as heard by the driver. Assume that the driver is located 1.0 m from each of the two front speakers and 1.5 m from each of the two rear speakers.Express your answer numerically in watts per meter squared.The threshold of hearing is defined as the minimum discernible intensity of the sound. It is approximately 10^?12W/m^2. Find the distance d from the car at which the sound from the stereo can still be discerned. Assume that the windows are rolled down and that each speaker actually produces 0.06 W of sound, as suggested in the last follow-up comment.
Physics
1 answer:
frez [133]3 years ago
4 0

Answer:

a.  <em>4.77  </em>W/m^{2}

b. 2.122 W/m^{2}

c. <em>13.78</em> W/m^{2}

d. <em>69 km</em>

Explanation:

a.

power P of speaker = 60 W

distance d of speaker = 1.0 m

intensity I of speaker = P/4πd^{2}

I = 60/(4 x 3.142 x 1^{2}) = 60/12.568

Intensity = <em>4.77  </em>W/m^{2}

b.

at a distance of 1.5 m, intensity will be

I = P/4πd^{2}

I = 60/(4 x 3.142 x 1.5^{2}) = 60/28.278

Intensity = 2.122 W/m^{2}

c.

combined intensity of the two front speakers will be 2 x 4.77 = 9.54 W/m^{2}

combined intensity of the two back speaker will be 2 x 2.122 = 4.244 W/m^{2}

<em>total sound intensity perceived by the driver will be the superimposition of these four speakers.</em>

I = 9.54 + 4.244 =<em> 13.78</em> W/m^{2}

d.

Minimum discernible intensity of sound = 10^{-12} W/m^{2}

each speaker produces 0.06 W of power.

<em>We assume that each speaker spreads outward evenly.</em>

from<em> I = P/4π</em>d^{2}<em>,</em>

d = \sqrt{\frac{P}{4*\pi*I } }

d = \sqrt{\frac{0.06} {4*\pi*10^{-12 } } = 69094.35 m ≅ <em>69 km</em>

You might be interested in
Trong chân không khi hai điện tích cách nhau lần lượt là d và d+10cm thì lực tương tác điện giữa chúng có độ lớn tương ứng là 2.
Cerrena [4.2K]

Answer:

H2O is also known as for water

5 0
2 years ago
Take another look at lines 2 and 3. Suppose you use distance and time between any pair of neighboring dots to calculate speed:
Nataly [62]

Answer:

Add the two speeds together.

Then, divide the sum by two. This will give you the average speed for the entire trip. So, if Ben traveled 40 mph for 2 hours, then 60 mph for another 2 hours, his average speed is 50 mph.

8 0
3 years ago
Read 2 more answers
A series of bright fringes appears on the viewing screen of a Young's double-slit experiment. Suppose you move from one bright f
goblinko [34]
Ahahaha fidjdsd skssjsjsbs SJSU’s
6 0
3 years ago
6. A dumb, bored child wants to see what will happen if they jump off the top of their shed with an umbrella. As you can guess,
ale4655 [162]

Answer:

All i kno is that that kid ain't gonna be ok

Explanation:

if u tell me how to do it ill do it

5 0
3 years ago
Two tuning forks, 254 Hz. and 260 Hz., are struck simultaneously. How many beats will be heard?
Lisa [10]

The longer you continue to listen, the more beats will be heard.

They'll occur at the rate of (260Hz - 254Hz) = 6 Hz .
 
7 0
3 years ago
Other questions:
  • the process of making alloys involves _____ pure metals to remove impurities. Then the pure metals are ____ with other component
    11·2 answers
  • What is the net displacement of the particle between 0 seconds and 80 seconds?
    11·1 answer
  • A 20.0 μf capacitor is charged to a potential difference of 850 v. the terminals of the charged capacitor are then connected to
    14·1 answer
  • What are cosmic rays mostly made up of?
    5·1 answer
  • A force pair is produced when a tennis racket strikes a tennis ball. Which of the following best explains why the tennis ball do
    8·1 answer
  • O2 is a molecule.
    8·1 answer
  • The environment between the outer and inner nuclear membranes is most accurately referred to as the:
    11·1 answer
  • How many neutrons are in the nucleus of an atom with an atomic mass of 80 A.M.U. and an atomic number of 35?
    10·1 answer
  • Please help me, I beg you​
    12·1 answer
  • The cheetah is considered the fastest running animal in the world. Cheetahs can accelerate to a speed of 21.5 m/s in 2.50 s and
    9·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!