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
Nataly [62]
3 years ago
14

A rock group is playing in a bar. Sound emerging from the door spreads uniformly in all directions. The intensity level of the m

usic is 116 dB at a distance of 2.82 m from the door. At what distance is the music just barely audible to a person with a normal threshold of hearing? Disregard absorption. Answer in units of m.
Physics
2 answers:
LekaFEV [45]3 years ago
5 0

Answer:

1779299.7m

Explanation:

From formulas in acoustic sound, we know that sound intensity is inversely proportional to the square of the distance away.

Thus;

I2/I1 = r2²/r 1²

So,

∆L = 10 log (I2/I1)

Where ∆L is the intensity of music and r1 and r2 are distances away.

∆L=10log 10(r1²/r2²)

∆L=10log 10(r1/r2)²

∆L= - 20log 10(r1/r2)

r2 = r1•10^(-∆L/20)

​From the question,

∆L = 116 Db

r1 = 2.82m

Thus,

r2 = 2.82 x 10^(116/20)

r2 = 2.82 x 630957.34 = 1779299.7m

sergij07 [2.7K]3 years ago
5 0

Answer / Explanation:

To properly answer this question, let us first define what sound intensity is:

Sound intensity which can also be refereed to as also known as acoustic intensity can be described as the calculated power or energy needed to transmit sound waves per unit area in a direction at 90 degree to that area. We should also note that the SI unit of sound intensity is the watt per square meter.

Referring back to the question asked,

To find where the music is barely audible, we need to use the equation

L₂ = L₁ - 20 log r₂/r₁

where  

L₁ = Sound level in decibels, as well as the

r₁ =  distance from the source that sound level is heard, and  

L₂ = Sound level, while

r₂ =  distance at a different point.

Moving forward,

To be able to find where the sound is barely audible, we need to find the location at which the sound level is zero db (o db).

Therefore,

L₂ = L₁ - 20 log r₂ / r₁

0dB  =  116 dB  −  20log  r₂ / 2.82 m 20  log  r₂ / 2.82 m

= 116 dB r₂ / 2. 82m = 10 ∧ 116 / 20

r₂ = (2.82m) 10 ∧ 116 / 20

r₂ =  178.7m

You might be interested in
Which of the following is not an example of kinetic energy being converted to potential energy?
KengaRu [80]

The list of choices you provided with your question
is utterly devoid of any such examples.

6 0
3 years ago
Read 2 more answers
An object's describes it's distance and direction from a reference point .
Ainat [17]

6: velocity i hpe this is what your looking for

4 0
3 years ago
Read 2 more answers
Andrea's near point is 20.0 cm and her far point is 2.0 m. Her contact lenses are designed so that she can see objects that are
Shalnov [3]

Answer:

the closest distance that she can see an object clearly when she wears her contacts is 22.2 cm

Explanation:

Given the data in the question,

near point = 20 cm

far point = 2 m = 200 cm

Now, for an object that is infinitely far away, the image is at is its far point.

so using the following expression, we can determine the focal length

1/f = 1/i + 1/o

where f is the focal length, i is the image distance and o is the object distance.

here, far point i = 2 m = 200 cm  and v is ∞

so we substitute

1/f = 1/(-200 cm)  +  1/∞

f = -200 cm

Also, for object at its closest point, the image appear at near point,

so

1/f = 1/i + 1/o

we make o the subject of formula

o = ( i × f ) / ( i - f )

given that near point i = 20 cm

we substitute

o = ( -20 × -200 ) / ( -20 - (-200) )

o = 4000 / 180

o = 22.2 cm

Therefore, the closest distance that she can see an object clearly when she wears her contacts is 22.2 cm

4 0
3 years ago
What is a similarity for heat and temperature
Alex787 [66]
It is the subtance betwen  the person or the object 
7 0
3 years ago
Read 2 more answers
A small 24 kilogram canoe is floating downriver at a speed of 2 m/s. What is the canoe's kinetic energy?
USPshnik [31]
J can get answer on this way:
Ek=m*V*V/2= (24kg*2m/s*2m/s)/2=48 Ј
3 0
4 years ago
Other questions:
  • The 0.8-Mg car travels over the hill having the shape of a parabola. When the car is at point A, it is traveling at 9 m/s and in
    12·1 answer
  • What principle do all modern cameras use to form images ?
    15·2 answers
  • Consider light energy that is momentarily absorbed in glass and then re-emitted. Compared to the absorbed light, the frequency o
    5·1 answer
  • A certain superconducting magnet in the form of a solenoid of length 0.26 m can generate a magnetic field of 7.5 T in its core w
    9·1 answer
  • A radio station transmits to a receiving antenna. The radio wave sent is a
    11·1 answer
  • A tortoise and hare start from rest and have a race. As the race begins, both accelerate forward. The hare accelerates uniformly
    7·1 answer
  • When an object is stationary, all of the forces acting on it are balanced
    14·2 answers
  • Which best compares kinetic energy and temperature?
    11·2 answers
  • A 35 kg boy is riding a 65 kg go-cart. He pushes on the gas pedal, causing the cart to accelerate at 5 m/s2. Use the equation F
    6·2 answers
  • 10.
    15·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!