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Lady bird [3.3K]

3 years ago

6

I did questions 2 and 3 but I don't know if they are right. Someone help!

2 answers:

Tems11 [23]3 years ago

8 0

You got it right my friend

Alex73 [517]3 years ago

8 0

Yes they are correct

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A sinusoidal electromagnetic wave is propagating in vacuum. At a given point P and at a particular time, the electric field is i

olasank [31]

Answer:

a

The direction of the wave propagation is the negative z -axis

b

The amplitude of electric and magnetic field are $A_E= 3.35*10^5 V/m$ ,

$A_M= 1.12 *10^{-3} T$ respectively

Explanation:

According to right hand rule, your finger (direction of electric field) would be pointing in the positive x-axis i.e towards your right let your palms be face toward the direction of the magnetic field i.e negative y-axis (toward the ground ) Then anywhere your thumb stretched out is facing is the direction of propagation of the wave here in this case is the negative z -axis

The Intensity of the wave is mathematically represented as

$I = \frac{1}{2} c \epsilon _O E_{rms}^2$

Given that $I = 7.43 \frac{kW}{cm^2} = 7.43 \frac{*10^3}{*10^-{4} }= 7.43*10^7 \frac{W}{m^2}$

Making $E_{rms}$ the subject we have

$E_{rms} = \sqrt{\frac{I}{0.5*c*\epsilon_o} }$

Substituting values as given on the question

$E_{rms} = \sqrt{\frac{7.43 *10^7[\frac{W}{m^2} ]}{0.5 * 3.08*10^8 *8.85*10^{-12}} }$

$= 2.37*10^5 \ V/m$

The amplitude of the electric field is mathematically represented as

$A_E = \sqrt{2} * E_{rms}$

$= \sqrt{2} * 2.37*10^5$

$A_E= 3.35*10^5 V/m$

The amplitude of the magnetic field is mathematically represented as

$A_M = \frac{A_E}{c}$

Substituting value

$A_M = \frac{3.35 *10^5}{3.0*10^8}$

$A_M= 1.12 *10^{-3} T$

7 0

3 years ago

At takeoff, a commercial jet has a speed of 72 m/s. Its tires have a diameter of 0.89 m. Part (a) At how many rev/min are the ti

34kurt

Answer:

a) Revolutions per minute = 2.33

b) Centripetal acceleration = 11649.44 m/s²

Explanation:

a) Angular velocity is the ratio of linear velocity and radius.

Here linear velocity = 72 m/s

Radius, r = 0.89 x 0. 5 = 0.445 m

Angular velocity

$\omega =\frac{72}{0.445}=161.8rad/s$

Frequency

$f=\frac{2\pi}{\omega}=\frac{2\times \pi}{161.8}=0.0388rev/s=2.33rev/min$

Revolutions per minute = 2.33

b) Centripetal acceleration

$a=\frac{v^2}{r}$

Here linear velocity = 72 m/s

Radius, r = 0.445 m

Substituting

$a=\frac{72^2}{0.445}=11649.44m/s^2$

Centripetal acceleration = 11649.44m/s²

6 0

2 years ago

A satellite at a particular point along an elliptical orbit has a gravitational potential energy of 4700 MJ with respect to Eart

erastovalidia [21]

during satellite motion we know that total energy is always conserved

so here we will have

$KE_i + PE_i = KE_f + PE_f$

here we know that

$KE_i = 4800 MJ$

$PE_i = 4700 MJ$

now at other position

$PE_f = 6000 MJ$

now from above equation we have

$4800 +4700 = 6000 + KE$

now we have

$9500 = 6000 + KE$

$KE = 9500 - 6000 = 3500 MJ$

so its kinetic energy will be 3500 MJ

6 0

3 years ago

What do butterflies have on their feet which allows them to sense different strengths and types of nectar?

Andru [333]

The answer is D for sure.

4 0

2 years ago

Read 2 more answers

At a constant pressure, 10 L of a gas at 546 K is cooled to 273 K

lisabon 2012 [21]

Answer:

5 L

Explanation:

Ideal gas law:

PV = nRT

If P, n, and R are constant, then:

n₁R/P₁ = n₂R/P₂

Using ideal gas law, we can rewrite this as:

V₁/T₁ = V₂/T₂

This is known as Charles' law.

Plugging in values:

10 L / 546 K = V / 273 K

V = 5 L

8 0

3 years ago