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
Lực hút trái đất là dì
nataly862011 [7]
Lực hút trái đất gọi Là trọng lực
5 0
3 years ago
What are the functions of the female reproductive system?
gulaghasi [49]

The female reproductive system is designed to carry out several functions. It produces the female egg cells necessary for reproduction, called the ova or oocytes. The system is designed to transport the ova to the site of fertilization.

7 0
3 years ago
A circuit has a voltage of 10 V and a current of 5 A. What must the resistance be?
azamat

Answer:

R=V/I

R= 2

Explanation:

R = 10V/5A

R = 2ohms

3 0
3 years ago
A force of 200N due South and another force of 300N due East each act on an object simultaneously.
dangina [55]

Answer:

a) 500

b)-500, north west

Explanation:

a) sum of F= F1+F2= 200+300= 500

b) sum of forces=0

so 200+300-500+0

4 0
2 years ago
What does it mean for a reaction to be endothermic? choose 2 of the following
Rainbow [258]

Answer: I would choose options C and D

Explanation:

3 0
2 years ago
Read 2 more answers
Other questions:
  • The volume of a liquid is often given in
    7·1 answer
  • The planet zeta has 2 times the gravitational field strength and sane mass as the earth , how does the radius of zeta compare wi
    15·1 answer
  • Comparing objects in a related group can reveal patterns among them. These patterns in turn can help us learn more about those o
    5·1 answer
  • Monochromatic light is incident on a grating that is 75 mmwide
    8·1 answer
  • HELP PLS! What is the power when a crane lifts a piece of pipe from the ground to a certain height, doing 15000 J of work in 25s
    13·1 answer
  • G Railroad tracks are made from segments L = 79 m long at T = 20° C. When the tracks are laid, the engineers leave gaps of width
    7·1 answer
  • 5. The force of gravity acting on the object is object’s ______________.
    8·1 answer
  • A 95-kg astronaut is stranded from his space shuttle. He throws a 2-kg hammer away from the shuttle with a velocity of 19 m/s .
    11·1 answer
  • What noncontact forces act on an object that are balanced
    6·1 answer
  • The volume in the pump when the pump piston is all the way down represents the _______
    10·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!