help please i don’t know

Answer:

The correct option is B. 7.5 * 10¹⁴ Hz

Explanation:

Frequency = (speed) / (wavelength)

= (3 x 10⁸ m/s) / (4 x 10⁻⁷ m)

= (3/4 x 10¹⁵) ( m / m - s )

= (0.75 x 10¹⁵) /sec

= 7.5 x 10¹⁴ Hz

= 750,000 GHz

Answer:

Mark Brainliest please

answer is

Explanation:

For any wave,              

                          Frequency = (speed) / (wavelength)

                                             = (3 x 10⁸ m/s) / (4 x 10⁻⁷ m)

                                             = (3/4 x 10¹⁵)  ( m / m - s )

                                             = (0.75 x 10¹⁵)  /sec

                                             =  7.5 x 10¹⁴  Hz

                                             =   750,000 GH

Answer:

the answer is 9

Explanation:

because is 9

Answer:

1.37 mm²

Explanation:

From the image attached below:

Let's take a look at the two rays r and r' hitting the same mirror from two different positions.

Let x be the distance between these rays.

[tex]d_o =[/tex] distance between object as well as the mirror

[tex]d_{eye}[/tex] = distance between mirror as well as the eye

Thus, the formula for determining the distance between these rays can be expressed as:

[tex]x = 2d_o tan \theta[/tex]

where; the distance between the eye of the observer and the image is:

[tex]s = d_o + d_{eye}[/tex]

Then, the tangent of the angle θ is:

[tex]tan \theta = \dfrac{R}{d_o+d_{eye}}[/tex]

replacing [tex]tan \theta = \dfrac{R}{d_o+d_{eye}}[/tex] into [tex]x = 2d_o tan \theta[/tex], we have:

[tex]x = 2d_o \Big( \dfrac{R}{d_o+d_{eye}}\Big)[/tex]

[tex]x = 2(10) \Big( \dfrac{0.25}{10+28}\Big)[/tex]

[tex]x = 20\Big( \dfrac{0.25}{38}\Big) cm[/tex]

x = (0.13157 × 10) mm

x = 1.32 mm

Finally, the area A = π r²

[tex]A = \pi(\frac{x}{2})^2[/tex]

[tex]A = \pi(\frac{1.32}{2})^2[/tex]

A = 1.37 mm²

Answer:

a)  fem = - 2.1514 10⁻⁴ V,  b) I = - 64.0 10⁻³ A, c)    P = 1.38  10⁻⁶ W

Explanation:

This exercise is about Faraday's law

         fem = [tex]- \frac{ d \Phi_B}{dt}[/tex]

where the magnetic flux is

        Ф = B x A

the bold are vectors

        A = π r²

we assume that the angle between the magnetic field and the normal to the area is zero

         fem = - B π 2r dr/dt = - 2π B r v

linear and angular velocity are related

        v = w r

        w = 2π f

        v = 2π f r

we substitute

        fem = - 2π B r (2π f r)

        fem = -4π² B f r²

For the magnetic field of Jupiter we use the equatorial field B = 428 10⁻⁶T

we reduce the magnitudes to the SI system

       f = 2 rev / s (2π rad / 1 rev) = 4π Hz

we calculate

       fem = - 4π² 428 10⁻⁶ 4π 0.10²

       fem = - 16π³ 428 10⁻⁶ 0.010

       fem = - 2.1514 10⁻⁴ V

for the current let's use Ohm's law

        V = I R

        I = V / R

         I = -2.1514 10⁻⁴ / 0.00336

         I = - 64.0 10⁻³ A

Electric power is

        P = V I

        P = 2.1514 10⁻⁴ 64.0 10⁻³

        P = 1.38  10⁻⁶ W

Answer:

One can write F = K d^-2  where K = G M m

So dF/dd = -2 K d^-3 =   -2 K / d^3    (As d increases F decreases - it is opposite to the direction of F)

Answer:

ewjefkljlajwawk;dlqa;wdka:WDKkjlhgzkljwidaJLdkjALIw

Explanation:

Group of answer choices.

a) the capacity to learn from experience, solve problems, and to adapt to new situations.

b) how behavior changes as a result of experience.

c) the factors directing behavior toward a goal.

d) the ability to generate novel

Answer:

a) the capacity to understand the world, think rationally, and use resources effectively.

Explanation:

Psychology can be defined as the scientific study of both the consciousness and unconsciousness of the human mind such as feelings, emotions and thoughts, so as to understand how it functions and affect human behaviors in contextual terms.

This ultimately implies that, psychology focuses on studying behaviors and the mind that controls it.

In this scenario, Ashley who is a psychology major, stated that she's interested in the study of intelligence.

Intelligence can be defined as a measure of the ability of an individual to think, learn, proffer solutions to day-to-day life problems and effectively make informed decisions.

In other words, Ashley is interested in the capacity of humans to understand the world, think rationally, and use resources effectively to produce goods and services that meet the unending requirements, needs or wants of the people (consumers or end users) living around the world.

Answer:

Abby is standing (4.5^2 + 2.3^2)^1/2   from the far speaker

D2 = 5.05 m from the far speaker

The difference in distances from the speakers is

5.05 - 4.5 = .55 m     (Let y be wavelength, lambda)

n y = 4.5

(n + 1) y = 5.05 for the speakers to be in phase at smallest wavelength

y = .55 m          subtracting equations

f = v / y = 340 / .55 = 618 / sec     should be the smallest frequency

Explanation:

N2 + H2 --> NH3

balance them:

N2 + 3 H2 --> 2 NH3

so if 6 moles of N2 react, 12 moles of NH3 will form.

(you have to look at the big number in front, in this case its N2 and 2 NH3, therefore the amount of N2 will produce double the amount of NH3 )

the longer the wavelength, lower the frequency. In the same manner, shorter the wavelength, higher will be the frequency.

Answer:

he is a baby art and design

Answer:

[tex]\triangle h_c =0.204m[/tex]

Explanation:

Diameter [tex]d=30cm[/tex]

Height [tex]h=90cm[/tex]

Fill height [tex]h_f=60cm[/tex]

Angular speed [tex]N=180rpm[/tex]

Generally the equation for Angular velocity is mathematically given by

[tex]\omega=\frac{2 \pi*N}{60}[/tex]

[tex]\omega=\frac{2 \pi*180}{60}[/tex]

[tex]\omega=18.85rads/s[/tex]

Generally the equation for Liquid surface is mathematically given by

[tex]\mu_s=h*\frac{\omega^2*0.15^2}{4*9.81}[/tex]

[tex]\mu_s=0.396m[/tex]

Therefore the liquid drop at center due to rotation is

[tex]\triangle h_c =h-\mu_s[/tex]

[tex]\triangle h_c =0.60-0.396[/tex]

[tex]\triangle h_c =0.204m[/tex]

Answer:

Increase the rate and the same maximum energy of the electrons

Explanation:

According to the photoelectric effect we can say:

I hope it helps you!

Answer:

Various uses of water :

1. Water is used for daily purpose like cooking , bathing , cleaning and drinking.

2. Water used as a universal solvent.

3. water maintains the temperature of our body.

4. Water helps in digestion in our body.

5 .water is used in factories and industries.

6. Water is used to grow plants , vegetables and crops.

Answer:

ω₁ = 2.2 rev/s

Explanation:

Conservation of angular momentum

moment of inertia uniform disk is ½mR²

moment of inertia uniform rod about an end mL²/3

We can think of our rod as two rods of mass m/2 and length R

L = ½mR²ω₀

L = (½mR² + 2(m/2)R²/3)ω₁

ω₁ = ω₀(½mR² / (½mR² + mR²/3))

ω₁ = ω₀(½  / (½  + 1/3))

ω₁ = 0.6ω₀

ω₁ = 2.16

Answer:

(a) 5.46 C

(b) 3.4125 x 10^19

Explanation:

q' = 1.08 C, q'' = 6.74 C, q''' = 4.61 C, q'''' = 9.41 C

When the charges are in contact to each other.

(a) So, the net charge is

[tex]q = \frac{q' + q'' + q''' + q''''}{4}[/tex]

[tex]q = \frac{1.08+6.74+4.61+9.41}{4}\\\\q = 5.46 C[/tex]

(b) As the charge is positive in nature, so the protons are there. The number of protons is

[tex]n = \frac{q}{e}\\\\n = \frac{5.46}{1.6\times 10^{-19}}\\\\n = 3.4125\times 10^{19}[/tex]

Solution :

Owing to the continuous attraction and repulsion force caused by the magnet or the electromagnet around the core of the motor produces a unidirectional torque whose direction is given by the Lorentz force, [tex]$F=q(\vec v \times \vec B)$[/tex], and thus the torque causes the rotation of the electric motor.

Removing half the insulation from the coil makes it to rotate just half a turn. When the half insulation is removed, the coil turns half and the rest of the time the connection terminates. The rest half turn will be provided by the angular momentum. Now after this half turn by the angular momentum, the connections will again be connected and again the torque will work on it to rotate the half turn. This continues and the motor rotates.

Answer:

181 is the answer I think so

Complete Question

Partial tides __________.

Question 7 options:  

a. represent various components of local tides that are resolved mathematically  

b. are added together to predict the height and timing of astronomical tides  

c. consist of 4 components due to the influence of celestial bodies  

d. consist of up to 60 components due to astronomical and non-astronomical factors  

e. All of the above except c are correct.

Answer:

Option E

Explanation:

Generally

Partial tides represent various components of local tides that are resolved mathematically

Partial tides  are added together to predict the height and timing of astronomical tides

Partial tides consist of up to 60 components due to astronomical and non-astronomical factors

But Partial tides do not consist of 4 components due to the influence of celestial bodies

Therefore

All of the above except c are correct.

Option E

Answer:

The length of the wire is "1.93 m".

Explanation:

Given:

Current,

I = 0.66 A

Angle,

[tex]\Theta[/tex] = 58°

Magnetic field of magnitude,

F = [tex]5.5\times 10^{-5}[/tex] N

The length of the wire will be:

⇒ [tex]F = B\times I\times L\times Sin \Theta[/tex]

or,

⇒ [tex]L = \frac{F}{B\times I\times Sin \theta}[/tex]

By putting the values, we get

       [tex]=\frac{5.5\times 10^{-5}}{0.66\times 5.1\times 10^{-5}\times Sin \ 58^{\circ}}[/tex]

       [tex]=\frac{5.5}{2.828}[/tex]

       [tex]=1.93 \ m[/tex]

Answer:

It will travel 350 meters each second.

Explanation:

The unit rate, 350 m/s, tells us that the jet will travel 350 meters per every second elapsed.

Answer:

5.83 seconds

Explanation:

60 seconds in 1 minute

350 meters per second

350/60

=5.83

Answer:

Explanation:

According to the Fleming's right hand rule, if we spread our right hand such that the thumb, fore finger and the middle finger are mutually perpendicular to each other, then the thumb indicates the direction of force, fore finger indicates the direction of magnetic field, then the middle finger indicates the direction of induced current.

According to the Lenz's law, the direction of induced emf is such that it always opposes the cause due to which it is produced.

Answer:

In sof the friction with the nylon is very small and the current with the line e is largeummary

Explanation:

When we rub the shoes against the carpet, static electricity is produced, when you touch the metal knob you close the circuit and the current can circulate to three of the body, the value of this current is of the order of micro volts, for which a small discharge, the power that circulates through the body is very small of the order of 0.005 A

When you touch the power line, the voltage may be small, but the amount of current that can generate them is of the order of tens of amps, the electric shock is much greater per location.

In general there is a rule that if the body resumes more than P = 4000W the discharge could be fatal.

In sof the friction with the nylon is very small and the current with the line e is largeummary, the difference is that the current at the stop , so the paper that passes through the body is large and can be dangerous.

In contact with metal doorknob, get a mild shock  while with power line of same voltage, fatal the body as the amount of current is more.

When the two materials are rubbed each other, then the electric charged generated between them.

This charging of materials, due to the rubbing of two materials against each other, is called the charging by friction.

It is easy to produce a potential difference of several thousand volts between the body and the floor by scuffing your shoes across a nylon carpet.

In this case, the potential difference may be higher, but the value of current is very low. Thus, when the body touches a metal doorknob, it will get a mild shock.

Now, in another case, the contact with a power line of comparable voltage would probably be fatal. This is because in the power line the amount of current is much higher.

Hence, in contact with metal doorknob, get a mild shock  while with power line of same voltage, fatal the body as the amount of current is more.

Learn more about the charging by friction here;

https://brainly.com/question/8418256

Answer:

the study of the past

Explanation:

dogs and cats

Answer:

|x| = √53

Explanation:

We are told that the vector starts at the point (0.0) and ends at (2,-7) .

Thus, magnitude of displacement is;

|x| = √(((-7) - 0)² + (2 - 0)²)

|x| = √(49 + 4)

|x| = √53

Answer:

a) ε = 14.7 μv

b) ε = 21 μv

Explanation:

Given the data in the question;

Diameter of solenoid; d = 3 cm

radius will be half of diameter,  so, r = 3 cm / 2 = 1.5 cm = 1.5 × 10⁻² m

Number of turns; N = 40 turns per cm = 4000 per turns per meter

Current; [tex]I[/tex] = 0.235 A

change in time Δt = 0.40 sec

Now,

We determine the magnetic field inside the solenoid;

B = μ₀ × N × [tex]I[/tex]  

we substitute

B = ( 4π × 10⁻⁷ Tm/A ) × 4000 × 0.235  

B = 1.1881 × 10⁻³ T

Now, Initial flux through the coil is;

∅₁ = NBA = NBπr²  

and the final flux  

∅₂ = 0        

so, the εmf induced ε = -Δ∅/Δt = -( ∅₂ - ∅₁ ) / Δt

= -( 0 - NBπr² ) / Δt  

= NBπr² / Δt    

a)

for N = 7

ε = [ 7 × ( 1.1881 × 10⁻³ ) × π( 1.5 × 10⁻² )² ] / 0.40

ε = 14.7 × 10⁻⁶ v

ε = 14.7 μv      

b)

for N = 10

ε = [ 10 × ( 1.1881 × 10⁻³ ) × π( 1.5 × 10⁻² )² ] / 0.40

ε = 21 × 10⁻⁶ v

ε = 21 μv  

Explanation:

Newton's second law is a quantitative description of the changes that a force can produce on the motion of a body. It states that the time rate of change of the momentum of a body is equal in both magnitude and direction to the force imposed on it.

Answer:

0A.Output force divided by input force.