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2 years ago

14

a sinusoidal electromagnetic wave has an electric field whose rms value is 100 V/m. What is the instantaneous rate S of energy f

low for this wave?

1 answer:

diamong [38]2 years ago

7 0

To solve this problem it is necessary to apply the concepts related to Energy Carried by Electromagnetic Waves.

The energy calculated per unit area per unit of time that crosses a plane perpendicular to the wave is called from the theory as energy flow and is usually denoted by the letter S.

Its calculation can be developed by dividing the energy by the area in the time interval, that is:

$S = \frac{\textrm{Energy passing Area in time t} }{At} = uc = \epsilon_0 c E^2$

Where,

$c = 3*10^8 m/s \rightarrow$ Speed of light

E = Electric field

$\epsilon = 8.85*10^{-12}F/m \rightarrow$ Vacuum permittivity

From the statement we are given the value of the electric field that is 100V / m, therefore:

$S = \epsilon_0 c E^2$

$S = (8.85*10^{-12})(3*10^8)(100)^2$

$S = 26.53W/m^2$

Therefore the instantaneous rate of energy flow for this wave is $S = 26.53W/m^2$

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Let $u$ be the initial velocity of the soccer ball at an angle of inclination of $\theta_0$ with the positive x-axis.

Given that:

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As "north" and "up" as the positive x ‑ and y ‑directions, respectively.

So, $g= -10 m/s^2$

As the acceleration due to gravity is in the vertical direction, so the horizontal component of the initial velocity remains unchanged.

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$\Rightarrow u_x=10$ m/s

So, the horizontal component of the velocity is 10 m/s which is constant and the graph has been shown in the figure (i).

Now, $u\cos(45^{\circ})=10$ [as $u_x=u\cos\theta_0$ ]

$\Rightarrow u=10\sqrt{2}$ m/s.

The vertical component of the initial velocity,

$u_y= u\sin\theta_0$

$\Rightarrow u_y=10\sqrt{2}\sin(45^{\circ})$

$\Rightarrow u_y=10$ m/s

Let v be the vertical component of the velocity at any time instant t.

From the equation of motion,

$v=u+at$

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In this case, we have $u=u_y, a= -10 m/s^2$ .

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2 years ago

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Answer:

at y=6.29 cm the charge of the two distribution will be equal.

Explanation:

Given:

linear charge density on the x-axis, $\lambda_1=8\times 10^{-6}\ C$

linear charge density of the other charge distribution, $\lambda_2=-6\times 10^{-6}\ C$

Since both the linear charges are parallel and aligned by their centers hence we get the symmetric point along the y-axis where the electric fields will be equal.

Let the neural point be at x meters from the x-axis then the distance of that point from the y-axis will be (0.11-x) meters.

<u>we know, the electric field due to linear charge is given as:</u>

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where:

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Therefore,

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Which of the following best describes a capacitor?

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Answer:

B

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2 years ago

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Answer:

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