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
dlinn [17]
2 years ago
8

A sinusoidal electromagnetic wave from a radio station passes perpendicularly through an open window that has area of 0.500 m2 .

At the window, the electric field of the wave has an rms value 0.0600 V/m .
How much energy does this wave carry through the window during a 30.0-s commercial? Express your answer with the appropriate units.
Physics
1 answer:
vesna_86 [32]2 years ago
3 0

Answer:

The energy of the wave is 1.435 x 10⁻⁴ J

Explanation:

Given;

area of the window, A = 0.5 m²

the rms value of the field, E = 0.06 V/m

The peak value of electric field is given by;

E_o = \sqrt{2} *E_{rms}\\\\E_o = \sqrt{2}*0.06\\\\E_o = 0.0849 \ V/m

The average intensity of the wave is given by;

I_{avg} = \frac{c \epsilon_o E_o^2 }{2}\\\\I_{avg} =  \frac{(3*10^8)( 8.85*10^{-12}) (0.0849)^2 }{2}\\\\I_{avg} = 9.569*10^{-6} \ W/m^2

The average power of the wave is given by;

P = I x A

P = (9.569 x 10⁻⁶ W/m²) (0.5 m²)

P = 4.784 x 10⁻⁶ W

The energy of the wave is given by;

E = P x t

E = (4.784 x 10⁻⁶ W)(30 s)

E = 1.435 x 10⁻⁴ J

Therefore, the energy of the wave is 1.435 x 10⁻⁴ J

You might be interested in
A block of mass 2 kg is placed on the floor. The coefficient of static friction is 0.4. A horizontal force of 2.5 N is applied o
Masja [62]

Answers is  F=7.84 N

Friction force resists the effect of horizontal force and trying to approch to a limiting force.

we have formula for limiting friction force between block and floor

               F=Ц N

where N=mg

putting values we get answer.

Download pdf
3 0
2 years ago
An 80 g, 40 cm long rod hangs vertically on a frictionless, horizontal axle passing through its center. A 15 g ball of clay trav
fiasKO [112]

Answer:

θ  = 12.95º

Explanation:

For this exercise it is best to separate the process into two parts, one where they collide and another where the system moves altar the maximum height

Let's start by finding the speed of the bar plus clay ball system, using amount of momentum

The mass of the bar (M = 0.080 kg) and the mass of the clay ball (m = 0.015 kg) with speed (v₀ = 2.0 m / s)

Initial before the crash

      p₀ = m v₀

Final after the crash before starting the movement

     p_{f} = (m + M) v

     p₀ = p_{f}

     m v₀ = (m + M) v

     v = v₀ m / (m + M)

     v = 2.0 0.015 / (0.015 +0.080)

     v = 0.316 m / s

With this speed the clay plus bar system comes out, let's use the concept of conservation of mechanical energy

Lower

    Em₀ = K = ½ (m + M) v²

Higher

    E_{mf} = U = (m + M) g y

   Em₀ = E_{mf}

   ½ (m + M) v² = (m + M) g y

   y = ½ v² / g

   y = ½ 0.316² / 9.8

   y = 0.00509 m

Let's look for the angle the height from the pivot point is

    L = 0.40 / 2 = 0.20 cm

The distance that went up is

     y = L - L cos θ

     cos θ  = (L-y) / L

     θ  = cos⁻¹ (L-y) / L

     θ  = cos⁻¹-1 ((0.20 - 0.00509) /0.20)

      θ  = 12.95º

4 0
3 years ago
The velocity of a motor bike of mass 140 kg is increased to 40m/s from 20m/s in 2 seconds. Then the force required for this is?
Liula [17]

Answer:

true blood season and answers the question of whether you are not the intended recipient you are not the intended recipient you are not the intended recipient

5 0
3 years ago
An electric motor rotating a workshop grinding wheel at 1.06 102 rev/min is switched off. Assume the wheel has a constant negati
kvasek [131]

Answer:

t = 106π / 30*2.1

Explanation:

w_{i} = 1.06*10^{2}    => 106

    => 106 x 2π/60

    => 106/30π

∝ = -2.1 rad/sec²

w_{f} => 0

w_{f} = w_{i} + ∝t

∴ (w_{f} - w_{i}) / ∝ = t

t = 106π / 30*2.1

6 0
3 years ago
I'm walking 1.6m/s to 7-11 and it started to rain so I sped up to 2.7m/s in 1.2
olga nikolaevna [1]

Answer:

Explanation:

a = \frac{v_f-v_0}{t} which is the final velocity minus the initial velocity in the numerator, and the change in time in the denominator.  For us:

a=\frac{2.7-1.6}{1.2} so

a = .92 m/s/s (NOT negative because you're speeding up)

5 0
3 years ago
Other questions:
  • What is the velocity of the object moving from 3 - 7 seconds?<br> O m/s<br> -6 m/s<br> 6 m/s
    5·1 answer
  • What does the churning air in the troposphere help determine
    9·1 answer
  • Which of the following are energy solutions that release pollution into the air? coal petroleum fuel cells wind energy oil nucle
    14·1 answer
  • What type of atom os K2CO3?
    7·1 answer
  • The characteristics of minerals: S I CC N. what does S I CC N. stand for
    12·1 answer
  • A 1.1-kg object is suspended from a vertical spring whose spring constant is 160 N/m. (a) Find the amount by which the spring is
    7·1 answer
  • On Distance Displacement Position vs. Time graphs. Velocity vs. Time graphs, and Acceleration vs. Time graphs, which vanable is
    11·1 answer
  • <img src="https://tex.z-dn.net/?f=%20%5Csf%20%7B%20%5Cfcolorbox%7Bgreen%7D%7Bg%7D%7B%20What%20are%20impulses%3F%7D%7D%20" id="Te
    11·1 answer
  • Define potential difference as used in electricity​
    9·2 answers
  • An astronomer observes two ordinary stars. the first one turns out to be twice as hot as the second. this means that the first o
    12·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!