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
Andrew [12]
3 years ago
15

A source emits sound uniformly in all directions. There are no reflections of the sound. At a distance of 12 m from the source,

the intensity of the sound is 3.5 × 10-3 W/m2. What is the total sound power P emitted by the source?
Physics
1 answer:
yaroslaw [1]3 years ago
7 0

Answer:

1.58 W

Explanation:

Since the sound spreads uniformly in all directions, it must be in a form of a circle with radius of 12 m. So the area of the circle is

A = \pi r^2 = \pi 12^2 = 452.389 m^2

From the intensity of the sound we can calculate the power at 12 m

P = AI = 452.389 * 3.5\times10^{-3} = 1.58 W

You might be interested in
A long line of charge with uniform linear charge density λ1 is located on the x-axis and another long line of charge with unifor
Dahasolnce [82]

Answer:

A.The positive z-direction

Explanation:

We are given that

Linear charge density of long line which is  located on the x-axis=\lambda_1

Linear charge density of another long line which is  located on the y-axis=\lambda_2

We have to find the direction of electric field at z=a on the positive z-axis if \lambda_1 and \lambda_2 are positive.

The direction of electric field  at z=a on the positive z-axis  is positive z-direction .

Because \lambda_1 and \lambda_2 are positive and the electric field is  applied away from the positive charge.

Hence, option A is true.

A.The positive z-direction

6 0
3 years ago
A 3.0 kg object moving 8.0 m/s in the positive x direction has a one-dimensional elastic collision with an object (mass = M) ini
finlep [7]
<h2>Option 2 is the correct answer.</h2>

Explanation:

Elastic collision means kinetic energy and momentum are conserved.

Let the mass of object be m and M.

Initial velocity object 1 be u₁,  object 2 be u₂

Final velocity object 1 be v₁,  object 2 be v₂

Initial momentum = m x u₁ + M x u₂ = 3 x 8 + M x 0 = 24 kgm/s

Final momentum = m x v₁ + M x v₂ = 3 x v₁ + M x 6 = 3v₁ + 6M

Initial kinetic energy = 0.5 m x u₁² + 0.5 M x u₂² = 0.5 x 3 x 8² + 0.5 x M x 0² = 96 J

Final kinetic energy = 0.5 m x v₁² + 0.5 M x v₂² = 0.5 x 3 x v₁² + 0.5 x M x 6² = 1.5 v₁² + 18 M

We have

            Initial momentum = Final momentum

            24 = 3v₁ + 6M

            v₁ + 2M = 8

             v₁ = 8 - 2M

            Initial kinetic energy = Final kinetic energy

            96 = 1.5 v₁² + 18 M

            v₁² + 12 M = 64

Substituting  v₁ = 8 - 2M

           (8 - 2M)² + 12 M = 64    

           64 - 32M + 4M² + 12 M = 64    

            4M² = 20 M

               M = 5 kg

Option 2 is the correct answer.  

6 0
3 years ago
3. Hahn determined that barium (atomic number 56) was one of the elements created when a uranium atom (atomic number 92) split .
creativ13 [48]

According to a periodic table, Krypton was created during the fission of Uranium.

<h3>What is the atomic number?</h3>

<em>Atomic</em> number is a characteristic associated with an element and indicates its number of protons, when a fision occurs, the total number protons is conserved.

Thus, the fission of uranium is led by two elements with <em>atomic</em> numbers 56 and 36. According to a periodic table, those <em>atomic</em> numbers are associated to elements Barium (Ba) and Krypton (Kr), respectively.

According to a periodic table, Krypton was created during the fission of Uranium. \blacksquare

To learn more on fission, we kindly invite to check this verified question:  brainly.com/question/6572079

8 0
2 years ago
A block of ice (m = 9 kg) at a temperature of T1 = 0 degrees C is placed out in the sun until it melts, and the temperature of t
jonny [76]

Answer:

a) An expression for the amount of energy, E_m, needed to melt the ice into water.

(E_m) = (m × Lf)

b) An expression for the total amount of energy, E_tot, to melt the ice and then bring the water to T2

(Total heat) = (m × Lf) + mc (T2 - T1)

c) 3,646,458 J = 3646.46 kJ

Explanation:

a) When a pure body changes its phase at meltimgbor boiling point, it does so at a constant temperature. When a pure body melts, the amount of heat responsible for this change is just given by a product od the mass of the body and the body's heat of fusion.

(E_m) = (m × Lf)

b) The Heat required to raise the temperature of a body from one temperature to another is given by the product of the mass of the body, its specific heat capacity and the temperature difference between the final point and the starting point.

(E_2) = mcΔT = mc (T2 - T1)

Total heat required to melt the ice at T1 = 0 and raise the temperature of the resulting water to T2 is then a sum of (E_m) + (E_2)

(Total heat) = (m × Lf) + mc (T2 - T1)

c) What is the energy in Joules?

(Total heat) = (m × Lf) + mc (T2 - T1)

m = mass of ice = resulting mass of water = 9 kg

Lf = latent heat of fusion = 334000 J/kg

c = Specific heat capacity of water = 4186 J/kg.K

T2 = final temperature of the water = 17°C

T1 = Initial temperature of the water = 0°C

Note that the units of temperature difference is the same for K and °C

(Total heat) = (m × Lf) + mc (T2 - T1)

Q = (9 × 334000) + [9 × 4186 × (17 - 0)]

Q = 3,006,000 + 640,458 = 3,646,458 J = 3646.46 kJ

Hope this Helps!!!

7 0
3 years ago
Which formula can be used to calculate the horizontal displacement of a horizontally launched projectile?
Jet001 [13]
I think D x=vxt because it's equation finding change of x (displacement) and using time
7 0
3 years ago
Other questions:
  • Determine if each phrase describes speed or velocity Sort each tile into the appropriate column
    8·1 answer
  • Which best describes what forms in nuclear fission?A. two smaller, more stable nucleiB. two larger, less stable nucleiC. one sma
    7·2 answers
  • Which statement describes the relationship of resistance and current
    6·1 answer
  • The radar gun measures the frequency of the radar pulse echoing off your car. By what percentage is the measured frequency diffe
    7·1 answer
  • An object exhibits SHM with an angular frequency w = 4.0 s-1 and is released from its maximum displacement of A = 0.50 m at t =
    8·1 answer
  • Question 11(Multiple Choice Worth 3 points)
    12·1 answer
  • Identify which type of source is being described.
    10·2 answers
  • Apples are stored in a container (width = length = 3.5 ft) that is filled to a depth of 2.75 feet. If the unit density of an app
    10·1 answer
  • Sedimentary layers that are deposited on an angle are called?
    10·1 answer
  • Would you expect the density of graphite and diamond to be the same
    7·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!