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3 years ago

An electromagnetic wave has a frequency of and is traveling in a vacuum. The magnetic field is given by ______.

Physics

1 answer:

Reptile [31]3 years ago

4 0

Answer:

c) true. With the magnetic field you can determine the Poynting vector and this is equal to the intensity of the wave

Explanation:

An electromagnetic wave carries energy that is given by the vector of poyntíng

S = 1 / μ₀ E x B

The electric and magnetic fields are related

E = c B

Substituting

S = c /μ₀ B² / 2

The two comes from the average value

Let's examine the claims

a) false to determine the wavelength the frequency is needed

b) False. To find the electric field you need the magnetic field

c) true. With the magnetic field you can determine the Poynting vector and this is equal to the intensity of the wave

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A 750-newton person stands in an elevator that is

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When an elevator is accelerating downward, the normal force is equal to mg-ma (hence you feel a little lighter when accelerating downwards)

Therefore, the upward force of the elevator floor on the person must be less than 750N

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What is a bond between a positive and a negative ion charge?

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Answer:

Ionic Bond

Explanation:

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3 years ago

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The depth of the Pacific Ocean in the Mariana Trench is 36,198 ft. What is the gauge pressure at this depth

FinnZ [79.3K]

Answer:

the pressure at the depth is 1.08 × $10^{8}$ Pa

Explanation:

The pressure at the depth is given by,

P = h $\rho$ g

Where, P = pressure at the depth

h = depth of the Pacific Ocean in the Mariana Trench = 36,198 ft = 11033.15 meter

$\rho$ = density of water = 1000 $\frac{kg}{m^{3} }$

g = acceleration due to gravity ≈ 9.8 $\frac{m}{s^{2} }$

P = 11033.15 × 9.8 × 1000

P = 1.08 × $10^{8}$ Pa

Thus, the pressure at the depth is 1.08 × $10^{8}$ Pa

4 0

3 years ago

Problem One: A beam of red light (656 nm) enters from air into the side of a glass and then into water. wavelength, c. and speed

Ivanshal [37]

Answer:

Part a)

$f_w = f_g = 4.57 \times 10^{14} Hz$

Part b)

$\lambda_w = 492 nm$

$\lambda_g = 437.3 nm$

Part c)

$v_w = 2.25 \times 10^8 m/s$

$v_g = 2.0 \times 10^8 m/s$

Explanation:

Part a)

frequency of light will not change with change in medium but it will depend on the source only

so here frequency of light will remain same in both water and glass and it will be same as that in air

$f = \frac{v}{\lambda}$

$f = \frac{3 \times 10^8}{656 \times 10^{-9}}$

$f = 4.57 \times 10^{14} Hz$

Part b)

As we know that the refractive index of water is given as

$\mu_w = 4/3$

so the wavelength in the water medium is given as

$\lambda_w = \frac{\lambda}{\mu_w}$

$\lambda_w = \frac{656 nm}{4/3}$

$\lambda_w = 492 nm$

Similarly the refractive index of glass is given as

$\mu_w = 3/2$

so the wavelength in the glass medium is given as

$\lambda_g = \frac{\lambda}{\mu_g}$

$\lambda_g = \frac{656 nm}{3/2}$

$\lambda_g = 437.3 nm$

Part c)

Speed of the wave in water is given as

$v_w = \frac{c}{\mu_w}$

$v_w = \frac{3 \times 10^8}{4/3}$

$v_w = 2.25 \times 10^8 m/s$

Speed of the wave in glass is given as

$v_g = \frac{c}{\mu_g}$

$v_g = \frac{3 \times 10^8}{3/2}$

$v_g = 2 \times 10^8 m/s$

4 0

3 years ago

A bottle rocket takes off with a = 34.5 m/s2. It

sergiy2304 [10]

Answer:3.4 seconds

Explanation:

Initial velocity(u)=0

acceleration=34.5m/s^2

Height(h)=200m

Time =t

h=u x t - (gxt^2)/2

200=0xt+(34.5xt^2)/2

200=34.5t^2/2

Cross multiply

200x2=34.5t^2

400=34.5t^2

Divide both sides by 34.5

400/34.5=34.5t^2/34.5

11.59=t^2

t^2=11.59

Take them square root of both sides

t=√(11.59)

t=3.4 seconds

8 0

3 years ago