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4 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]4 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 vessel with an unknown volume is filled with 10 kg of water at 90oC. Inspection of the vessel at equilibrium shows that 8 kg o

damaskus [11]

Hey there!

In this case, it is possible to solve this problem by using the widely-known steam tables which show that at 90 °C, the pressure that produces a vapor-liquid mixture at equilibrium is about 70.183 kPa (Cengel, Thermodynamics 5th edition).

Moreover, for the calculation of the volume, it is necessary to calculate the volume of the vapor-liquid mixture, given the quality (x) it has:

$x=\frac{m_{steam}}{m_{total}}$

Thus, since 8 kg correspond to liquid water, 2 kg must correspond to steam, so that the quality turns out:

$x=\frac{2kg}{10kg} =0.20$

Now, at this temperature and pressure, the volume of a saturated vapor is 2.3593 m³/kg whereas that of the saturated liquid is 0.001036 m³/kg and therefore, the volume of the mixture is:

$v=0.001036m^3/kg+0.2(2.3593-0.001036 )m^3/kg=0.4727m^3/kg$

This means that the volume of the container will be:

$V=10kg*0.4727m^3/kg\\\\V=4.73m^3$

Regards!

8 0

3 years ago

Why is Jupiter's rotation dangerous for human survivability?

krok68 [10]

Answer:

1. Why is Jupiter's rotation dangerous for human survivability?

Jupiter is the fastest rotating planet in our solar system. One day lasts about 9.5 Earth hours. This creates powerful winds that can whip around the planet at more than 300 mph. About 75 miles below the clouds, you reach the limit of human exploration.

2 .Why is Jupiter's planet axis tilt an issue for human survivability?

Jupiter, like Venus, has an axial tilt of only 3 degrees, so there is literally no difference between the seasons. ... The length of each season is roughly three years. Jupiter is the fastest spinning planet in our Solar System, which causes the planet to flatten at the poles and bulge at the equator.

3.Why is the diameter of Jupiter an issue for human survivability?

Since ,The Jupiter is so huge in mass ,The central force toward the centre will be high and we'll be forced toward it causing Several problems.

7 0

3 years ago

An 20-cm-long bicycle crank arm, with a pedal at one end, is attached to a 25-cm-diameter sprocket, the toothed disk around whic

Andrej [43]

Answer:

0.033815 m/s²

12.48810875 m

Explanation:

t = Time taken = 12 s

$\omega_f$ = Final angular velocity = 95 rpm

$\omega_i$ = Initial angular velocity = 64 rpm

$\alpha$ = Angular acceleration

$\theta$ = Angle of rotation

$\omega_f=\omega_i+\alpha t\\\Rightarrow \alpha=\frac{\omega_f-\omega_i}{t}\\\Rightarrow \alpha=\frac{95\times \frac{2\pi}{60}-64\times \frac{2\pi}{60}}{12}\\\Rightarrow \alpha=0.27052\ rad/s^2$

Tangential acceleration is given by

$a_t=\alpha r\\\Rightarrow a_t=0.27052\times 0.125\\\Rightarrow a_t=0.033815\ m/s^2$

The tangential acceleration of the pedal is 0.033815 m/s²

$\omega_f^2-\omega_i^2=2\alpha \theta\\\Rightarrow \theta=\frac{\omega_f^2-\omega_i^2^2}{2\alpha}\\\Rightarrow \theta=\frac{\left(95\times\frac{2\pi }{60}\right)^2-\left(64\times\frac{2\pi}{60}\right)^2}{2\times 0.27052}\\\Rightarrow \theta=99.90487\ rad$