Please can someone help me im struggling asap ill mark brainlist

3. The electric field of a sinusoidal electromagnetic wave has an amplitude of 5.0 V/m. How much radiation energy passes through

True [87]

Answer:

e) $179$ J

Explanation:

$E_{o}$ = Magnitude of electric field = 5 V/m

$A$ = Area of window = 1.5 m²

$c$ = speed of electromagnetic wave = 3 x 10⁸ m/s

$\Delta t$ = time interval = 1 h = 3600 sec

radiation energy is given as

$U = (0.5)\epsilon _{o}E_{o}^{2}cA\Delta t$

$U = (0.5)(8.85\times 10^{-12})(5)^{2}(3\times 10^{8})(1.5)(3600)$

$U = 179$ J

6 0

3 years ago

A coil with an inductance of 2.3 H and a resistance of 14 Ω is suddenly connected to an ideal battery with ε = 100 V. At 0.13 s

klemol [59]

Given Information:

Resistance = R = 14 Ω

Inductance = L = 2.3 H

voltage = V = 100 V

time = t = 0.13 s

Required Information:

(a) energy is being stored in the magnetic field

(b) thermal energy is appearing in the resistance

(c) energy is being delivered by the battery?

Answer:

(a) energy is being stored in the magnetic field ≈ 219 watts

(b) thermal energy is appearing in the resistance ≈ 267 watts

(c) energy is being delivered by the battery ≈ 481 watts

Explanation:

The energy stored in the inductor is given by

$U = \frac{1}{2} Li^{2}$

The rate at which the energy is being stored in the inductor is given by

$\frac{dU}{dt} = Li\frac{di}{dt} \: \: \: \: eq. 1$

The current through the RL circuit is given by

$i = \frac{V}{R} (1-e^{-\frac{t}{ \tau} })$

Where τ is the the time constant and is given by

$\tau = \frac{L}{R}\\ \tau = \frac{2.3}{14}\\ \tau = 0.16$

$i = \frac{110}{14} (1-e^{-\frac{t}{ 0.16} })\\i = 7.86(1-e^{-6.25t})\\\frac{di}{dt} = 49.125e^{-6.25t}$

Therefore, eq. 1 becomes

$\frac{dU}{dt} = (2.3)(7.86(1-e^{-6.25t}))(49.125e^{-6.25t})$

At t = 0.13 seconds

$\frac{dU}{dt} = (2.3) (4.37) (21.8)\\\frac{dU}{dt} = 219.11 \: watts$

(b) thermal energy is appearing in the resistance

The thermal energy is given by

$P = i^{2}R\\P = (7.86(1-e^{-6.25t}))^{2} \cdot 14\\P = (4.37)^{2}\cdot 14\\P = 267.35 \: watts$

(c) energy is being delivered by the battery?

The energy delivered by battery is

$P = Vi\\P = 110\cdot 4.37\\P = 481 \: watts$

4 0

3 years ago

If an object starts from rest, what is its initial velocity?

Vladimir79 [104]

Answer:

0 m/s

Explanation:

velocity= change in displacement/ time

at rest, the ball does not travel any distance

0/ t

=0

4 0

4 years ago

If the merry-go-round makes one revolution in 10 seconds, what is the child’s linear speed?

Anton [14]

The child's linear speed is

<em> (pi / 5) x (the child's distance from the center of the ride, in feet)</em>

feet per second.

5 0

3 years ago

What are some possible examples of genetic characteristics that can be passed down to child??????

elena-s [515]

They can have a close similar appearance to the parents, have close relation of child reactions.

for example, everyone born in my father's side of the family had the tendency to bump their head on something as they fall asleep up to the point when you are a toddler.

8 0

3 years ago

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