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
Vesnalui [34]
3 years ago
14

What is the speaker’s power output if the sound intensity level is 102 dBdB at a distance of 25 mm ? Express your answer to two

significant figures and include the appropriate units.
Physics
1 answer:
lesya [120]3 years ago
7 0

Answer:

Power  = 124.50 W

Explanation:

Given that:

The Sound intensity of a speaker output is 102 dB

and the distance r = 25 m

For the intensity of sound,

\beta (dB)= 10 \  log_{10 } (\dfrac{I}{I_o})

where;

the threshold of hearing   I_o = 10^{-12} (W/m^2)

\dfrac{102 }{10}= log_{10}( \dfrac{I}{10^{-12}})

10^{10.2} =  \dfrac{I}{10^{-12}}

I = 10^{10.2} \times 10^{-12}

I = 0.01585 W/m²

If we recall, we know remember that ;

Power = Intensity × A rea

Power = 0.01585 W/m² × 4 × 3.142 × (25 m)²

Power  = 124.50 W

You might be interested in
Consider the table below. Which of the following data sets depict an accelerating object? Mark all that apply.
Gre4nikov [31]

Answer:

A and B

Explanation:

The data sets that depict an accelerating object is Data Set A & Data Set B.

The both data sets show that the body is accelerating. Also, they show that the body started from rest (0m/s) at a 0sec.

Data Set A shows a non-constant acceleration which has changing amount of velocity with change in time. While Data Set B shows a constant acceleration which has constant amount of velocity with change in time.

7 0
3 years ago
The ground state energy of an oscillating electron is 1.23 eV. How much energy must be added to the electron to move it to the t
Vikki [24]

Answer:

  • The energy that must be added to the electron to move it to the third excited state is  -1.153 eV
  • The energy that must be added to the electron to move it to the fourth excited state is  -1.181 eV

Explanation:

Given;

Energy of electron in ground state (n = 1 ) = 1.23 eV

E₁ = 1.23 eV

Eₙ = E₁ /n²

where;

E₁ is the energy of the electron in ground state

n is the energy level,

For third excited state, n = 4

E₄ = E₁ /4²

E₄ = (1.23 eV) / 16

E₄ = 0.077 eV

Change in energy level, = E₄ - E₁ = 0.077 eV - 1.23 eV = -1.153 eV

The energy that must be added to the electron to move it to the third excited state is  -1.153 eV

For fourth excited state, n = 5

E₅ = E₁ /5²

E₄ = (1.23 eV) / 25

E₄ = 0.049 eV

Change in energy level, = E₅ - E₁ = 0.049 eV - 1.23 eV = -1.181 eV

The energy that must be added to the electron to move it to the fourth excited state is  -1.181 eV

5 0
3 years ago
If a pedestrian walked 900 meters forward and 300 meters back
serious [3.7K]

Answer:

B

Explanation:

5 0
2 years ago
In what order does light pass through structures of the eye? lens, cornea, retina cornea, pupil, lens pupil, iris, lens pupil, c
Mrrafil [7]

Answer: Light passes through the front of the eye (cornea) to the lens. The cornea and the lens help to focus the light rays onto the back of the eye (retina). The cells in the retina absorb and convert the light to electrochemical impulses which are transferred along the optic nerve and then to the brain.

Explanation:

When light rays reflect off an object and enter the eyes through the cornea (the transparent outer covering of the eye), you can then see that object. The cornea bends, or refracts, the rays that pass through the round hole of the pupil.

4 0
3 years ago
When you are riding in a car then the driver suddenly steps on the gas pedal, why do you feel a jolt and push back?
inessss [21]

Answer:

due to acceleration lol

4 0
2 years ago
Read 2 more answers
Other questions:
  • A 10 kg mass stretches a spring 70 cm in equilibrium. Suppose a 2 kg mass is attached to the spring, initially displaced 25 cm b
    14·1 answer
  • When the tube is filled with mercury vapor, as in this case, a sharp drop in the collected current is observed when the accelera
    10·1 answer
  • An astronaut has left the International Space Station to test a new space scooter. Her partner measures the following velocity c
    10·1 answer
  • Please help need answer asp
    14·2 answers
  • Elements in the family often have a similar
    6·2 answers
  • What is the average acceleration of a car that starts from
    12·2 answers
  • Una roca sobre una superficie de hielo está siendo tirada horizontalmente por tres cuerdas como se ve en la figura, donde F=95N,
    13·1 answer
  • Assume your mass is 84 kg. The acceleration due to gravity is 9.8 m/s 2 . How much work against gravity do you do when you climb
    15·1 answer
  • A sample contains 16 g of a radioactive isotope. how much radioactive
    14·2 answers
  • The figure below shows a motorcycle leaving the end of a ramp with a speed of 39.0 m/s and following the curved path shown. At t
    12·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!