please help!!!
In an electric motor, how do the permanent magnets and the electromagnet
interact?
PLEASE ANSWER FAST
A. The electromagnet causes the permanent magnets to reverse
poles.
B. The permanent magnets reverse the current in the electromagnet.

C. The electromagnet reverses the current in the permanent
magnets.
D. The permanent magnets cause the metal loop in the
electromagnet to turn.

if you don’t know don’t answer

(sorry something wrong w my keyboard so write each line for the explnation!)

63.0 m

Explanation:

Acceleration of car

=

v

−

u

t

=

0 ms

−

1

−

21.0 ms

−

1

6.00 s

=

−

3.50 ms

−

2

S

=

v

2

−

u

2

2a

S

=

(

0 ms

−

1

)

2

−

(

21.0 ms

−

1

)

2

2

×

−

3.50 ms

−

2

S

=

63.0

m

Answer:

Explanation:

all

Answer:

The answer is "[tex]W= 100.44 \ KJ\ \ \ \W_{win}=7.23 \ KJ[/tex]"

Explanation:

Please find the complete question in the attached file.

From of the ideal gas relation that initial and the last temperatures were determined:  

[tex]T_1 = \frac{P_1 V}{m R}[/tex]

    [tex]= \frac{100 \times 0.8}{1.54 \times 0.1889} \\\\ = 275 \ K[/tex]

[tex]T_2 = \frac{P_2 V}{m R}[/tex]

    [tex]= \frac{135 \times 0.8}{1.54 \times 0.1889} \\\\ = 317 \ K[/tex]

In the initial and final states, the internal energies for given temperatures are described from A-20 by means of intelmpolation and divided by the carlxon molar mass.  

[tex]u_1 = 141.56 \frac{KJ}{kg}\\\\u_2 = 206.78 \frac{KJ}{kg}[/tex]

The real job is just the difference between internal energies:  

[tex]W = m(u_2 - u_1) \\\\[/tex]

    [tex]= 1.54(206.78 -141.56) \ kJ \\\\ =100.44 \ kJ[/tex]

In the initial and final states, the zero entries are as determined as internal energies:

[tex]S_1^{\circ} =4.788 \frac{KJ}{kg K}\\\\S_2^{\circ} =5.0478 \frac{KJ}{kg K}[/tex]

From its energy increase, the minimum work required is determined:

[tex]W_{min} = m(u_2-u_1 - T_0(s_2 -S_1))\\\\=W-mT_0(S_2^{\circ}- S_1^{\circ} -R \In \frac{P_2}{P_1})\\\\= 100.44kJ -1.54 \times 298( 5.0478-4.788-0.1889 \In \frac{135}{100})\\\\=7.23\ KJ\\[/tex]

Answer:

Land pollution touches essentially every area of the living world, including: Water that isn't safe to drink. Polluted soil, which leads to a loss of fertile land for agriculture. Climate change, which causes an onslaught of disastrous problems, including flash floods and irregular rainfalls.

Explanation:

HOPE THIS HELPS!!!!!!

Answer:

Look at any ecosystem and there could be multiple forms of contamination—streams full of toxic chemicals from industrial processes, rivers overloaded with nutrients from farms, trash blowing away from landfills, city skies covered in smog. Even landscapes that appear pristine can experience the effects of pollution sources located hundreds or thousands of miles away.

Pollution may muddy landscapes, poison soils and waterways, or kill plants and animals. Humans are also regularly harmed by pollution. Long-term exposure to air pollution, for example, can lead to chronic respiratory disease, lung cancer and other diseases. Toxic chemicals that accumulate in top predators can make some species unsafe to eat. More than one billion people lack access to clean water and 2.4 billion don’t have adequate sanitation, putting them at risk of contracting deadly diseases.

Air pollution brings to mind visions of smokestacks billowing black clouds into the sky, but this pollution comes in many forms. The burning of fossil fuels, in both energy plants and vehicles, releases massive amounts of carbon dioxide into the atmosphere, causing climate change. Industrial processes also emit particulate matter, such as sulfur dioxide, carbon monoxide and other noxious gases. Indoor areas can become polluted by emissions from smoking and cooking. Some of these chemicals, when released into the air, contribute to smog and acid rain. Short term exposure to air pollution can irritate the eyes, nose and throat and cause upper respiratory infections, headaches, nausea and allergic reactions. Long-term exposures can lead to chronic respiratory disease, lung cancer, and heart disease. Long-term exposures also can lead to significant climatic changes that can have far reaching negative impacts on food, water and ecosystems. #SAVE OUR WORLD

Answer:

by determining the wavelength of the light emitted

Explanation:

The composition of the hot vaporized materials of an asteroid can be find out by the wavelength of the light emitted when the fragment material is burnt out.

Some of the asteroids that are very large do not burn completely in the atmosphere and they fall on the surface of the earth. Thus there is a possibility of radioactivity. An atom is radioactive or unstable when the forces that constitutes the nucleus are not balanced and then the nucleus have excess of energy. Thus these unstable and highly energetic nucleus will try to attain stability by ejecting protons and neutrons, or by releasing gamma rays, beta particles or positrons, etc. Thus they will radiate energy and will cause radioactivity.

Answer:

2.753*10^-11N

Explanation:

According to Newton's law of gravitation, the force between the masses is expressed as;

F = GMm/d²

M and m are the distances

d is the distance between the masses

Given

M = 3.71 x 10 kg

m = 1.88 x 10^4 kg

d = 1300m

G = 6.67 x 10-11 Nm²/kg

Substitute into the formula

F = 6.67 x 10-11* (3.71 x 10)*(1.88 x 10^4)/1300²

F = 46.52*10^(-6)/1.69 * 10^6

F = 27.53 * 10^{-6-6}

F = 27.53*10^{-12}

F = 2.753*10^-11

Hence the gravitational force between the asteroid is 2.753*10^-11N

Answer:

60 watts

Explanation:

Given that

Mass of the animal, m = 5 kg

Velocity of the animal, v = 10 m/s

Distance moved by the animal, d = 10 m

Drag force, F(d) = 12 N

Time taken, t = 2 seconds

To start with, we need to find the power output in itself before proceeding to find the average power output. And as such, we have

Power = Force * Distance/Time

But Distance/Time is velocity, so

Power = Force * Velocity

Power = 12 * 10

Power = 120 W.

We then use this power gotten to find the average power output.

Power(avg) = P/t

Power(avg) = 120 / 2

Power(avg) = 60 Watts.

Therefore, the average power output is found to be 60 Watts

Answer:

The value is      [tex]A = 39315 \ m^2[/tex]

Explanation:

From the question we are told that

    The velocity which the rover is suppose to land with is  [tex]v = 1 \ m/s[/tex]

    The  mass of the rover and the parachute is  [tex]m = 2270 \ kg[/tex]

     The  drag coefficient is  [tex]C__{D}} = 0.5[/tex]

      The atmospheric density of Earth  is  [tex]\rho = 1.2 \ kg/m^3[/tex]

     The acceleration due to gravity in Mars is  [tex]g_m = 3.689 \ m/s^2[/tex]

Generally the Mars  atmosphere density is mathematically represented as

          [tex]\rho_m = 0.71 * \rho[/tex]

=>        [tex]\rho_m = 0.71 * 1.2[/tex]

=>        [tex]\rho_m = 0.852 \ kg/m^3[/tex]

Generally the drag force on the rover and the parachute  is mathematically represented as

          [tex]F__{D}} = m * g_{m}[/tex]

=>       [tex]F__{D}} = 2270 * 3.689[/tex]  

=>       [tex]F__{D}} = 8374 \ N[/tex]  

Gnerally this drag force is mathematically represented as

         [tex]F__{D}} = C__{D}} * A * \frac{\rho_m * v^2 }{2}[/tex]

Here A is the frontal area

So  

         [tex]A = \frac{2 * F__D }{ C__D} * \rho_m * v^2 }[/tex]

=>       [tex]A = \frac{2 * 8374 }{ 0.5 * 0.852 * 1 ^2 }[/tex]

=>       [tex]A = 39315 \ m^2[/tex]

Answer:

8 joules

Explanation:

Just did it

Answer:

8 J

Explanation:

Potential energy = mass x gravitational field strength x height

Gravitational field strength is accelerations due to gravity which is 9.8m/s² ( you can round it up and take 10 as well)

Mass = Force ÷ Acceleration

20 ÷ 9.8 = 2.04

Potential energy = 2.04 x 9.8 x 0.40

= 7.99 = 8 J

Answer:

2.4s

Explanation:

The length of the pendulum = 75ft

Diameter d = 12 inches

The time period of the pendulum is given as

T = 2pi(L/g)^1/2

Then the time it takes to move from displacement to equilibrium is given as:

t = T/4

= (Pi/2)*(L/g)^1/2

= pi/2 x [(75x0.3048)/9.81]^0.5

= 1.57x[22.86/9.81)^0.5

= 2.4s

2.4 seconds is the least amount of time that it would take.

Answer:

D. Hydrogen combines with oxygen to form water.

Explanation:

Hydrogen combining with oxygen to form water is a typical example of chemical reaction.

During a chemical reaction, atoms of elements are rearranged. Most chemical reactions obey the law of conservation of mass which states that "matter is neither created nor destroyed in a chemical reaction but atoms are simply rearranged".

The other choices given are nuclear reactions. In such reactions, atoms are not rearranged but are simply destroyed and made in the process.

Answer:

D.) Hydrogen combines

Explanation:

BE HAPPY

Answer:

I think he was just trolling.

Explanation:

They don't give out any good reasons or evidence about him dying. I think they are just pretending. You tell me tho.... Many people think he did die, while others think that he didnt.

What do you think?!

Answer:

the answer is below

Explanation:

The diagram of the problem is given in the image attached.

Mass of rod AB = (0.4 m + 0.4 m) * 3 kg/m = 2.4 kg

Mass of rod OC = (1.5 m) * 3 kg/m = 4.5 kg

Mass of plate = 10 kg/m²[ (π* 0.3²) - (π* 0.1²)] = 2.513 kg

The center of mass is:

[tex]\hat{y}[2.4+2.513+4.5]=(0.75*4.5)+(2.513*0.5)\\\\\hat{y}=0.839\\\\I_{AB}=\frac{1}{12}*2.4*(0.4+0.4)^2= 0.128\ kg/m^2\\\\I_{OC}=\frac{1}{12}*4.5*(1.5)^2= 3.375\ kg/m^2\\\\I_{Gplate}=\frac{1}{2}*(\pi*0.3^2*10)*(0.3)^2-\frac{1}{2}*(\pi*0.1^2*10)*(0.1)^2= 0.126\ kg/m^2\\\\I_{plate}=I_{Gplate}+md^2=0.126+2.513(1.8^2)=8.27\ kg/m^2\\\\I_o=I_{plate}+I_{AB}+I_{OC}\\\\I_{o}=0.128+3.375+8.27=11.773\ kg/m^2 \\\\I_G=I_o-m_{tot}\hat{y}^2\\\\I_G=11.773-(9.413*0.839^2)\\\\I_G=5.147\ kg/m^2[/tex]

Answer:

The force of friction required to keep the car from sliding down the hill is 898.054 newtons and since [tex]f<f_{max}[/tex], the car will not slide down the hill.

Explanation:

The free body diagram is included below and now we prepare each equation of equilibrium for respective orthogonal axis:

[tex]\Sigma F_{x'} = f-m\cdot g \cdot \sin \theta = 0[/tex] (1)

[tex]\Sigma F_{y'} = N-m\cdot g \cdot \cos \theta = 0[/tex] (2)

Where:

[tex]f[/tex] - Static friction force, measured in newtons.

[tex]N[/tex] - Normal force from the inclined hill to the car, measured in newtons.

[tex]m[/tex] - Mass of the car, measured in newtons.

[tex]g[/tex] - Gravitational constant, measured in meters per square second.

[tex]\theta[/tex] - Angle of inclination of the hill, measured in sexagesimal degrees.

If we know that [tex]m = 1500\,kg[/tex], [tex]g = 9.807\,\frac{m}{s^{2}}[/tex] and [tex]\theta = 3.5^{\circ}[/tex], then the friction force required to keep the car from sliding down the hill is:

[tex]f = m\cdot g \cdot \sin \theta[/tex]

[tex]f = (1500\,kg)\cdot \left(9.807\,\frac{m}{s^{2}} \right)\cdot \sin 3.5^{\circ}[/tex]

[tex]f = 898.054\,N[/tex]

The force of friction required to keep the car from sliding down the hill is 898.054 newtons.

If the car does not slide down the hill, then the following condition must be observed:

[tex]f\le \mu_{s}\cdot m\cdot g \cdot \cos \theta[/tex] (2)

Where [tex]\mu_{s}[/tex] is the static coefficient of friction, dimensionless.

If we know that [tex]\mu_{s} = 0.45[/tex], [tex]m = 1500\,kg[/tex], [tex]g = 9.807\,\frac{m}{s^{2}}[/tex] and [tex]\theta = 3.5^{\circ}[/tex], then the maximum allowable static friction force is:

[tex]f_{max} = \mu_{s}\cdot m \cdot g \cdot \cos \theta[/tex]

[tex]f_{max} = (0.45)\cdot (1500\,kg)\cdot \left(9.807\,\frac{m}{s^{2}} \right)\cdot \cos 3.5^{\circ}[/tex]

[tex]f_{max} = 6607.378\,N[/tex]

Since [tex]f<f_{max}[/tex], the car will not slide down the hill.

Answer:

If there is a system of magnets being held in place, there is potential energy. When you let go the potential energy makes to kinetic energy and the magnets move.

Magnets cause objects to have kinetic energy as a result of the magnetic

force present in it.

Magnets is a material which has a strong metallic field which attracts

ferromagnetic substances such as steel, iron etc.

When  the magnets are put near these substances , the magnets attract them and causes them to move towards its direction . The magnets causes the conversion of the potential energy into kinetic energy through the strong metallic field.

Read more on https://brainly.com/question/19892755

Answer:

4.4 min

Explanation:

To solve this, we use the law of conservation of momentum

0 = -m(a).v(a) + m(c).v(c), where

m(a) = mass of the astronaut

m(c) = mass of the camera

v(a) = velocity of the astronaut

v(c) = velocity of the camera

Making v(a) subject of the formula, we have

v(a) = m(c).v(c)/m(a)

Now, we make one last assumption, that the astronaut is moving at constant speed and time, thus the time needed will be

t = s/v -> since s = vt

Now, we already have our v from above, so we substitute

t = s/[m(c).v(c)/m(a)]

t = s.m(a)/m(c).v(c)

Applying the values, we have

t = (41.4 * 70.1) / (0.916 * 12)

t = 2902.14 / 10.992

t = 264 seconds or 4.4 minutes

Answer:

v₃ = 22.67 [m/s]

Explanation:

In order to solve this problem, we must use the principle of conservation of the quantity of linear momentum. Where momentum is conserved before and after the collision, i.e. remains the same.

The terms on the left of the equation represent the amount of linear momentum before the collision and the members on the right represent the momentum after the collision.

[tex](m_{1}*v_{1})+(m_{2}*v_{2})=(m_{1}*v_{3})+(m_{2}*v_{4})[/tex]

where:

m₁ = mass of the truck = 3000 [kg]

m₂ = mass of the car = 1000 [kg]

v₁ = velocity of the truck before the coliision = 25 [m/s]

v₂ = velocity of the car parked = 0 (without movement)

v₃ = velocity of the truck after the collision [m/s]

v₄ = velocity of the car after the collision = 7 [m/s]

Now replacing:

[tex](3000*25)+(1000*0)=(3000*v_{3})+(1000*7)\\75000-7000 = 3000*v_{3}\\v_{3}=22.67 [m/s][/tex]

Answer:

because trains are bigger and heavier than cars.

Explanation:

Answer:

20kg

Explanation:

Given parameters:

Force  = 100N

Acceleration  = 5m/s²

Unknown:

Mass  = ?

Solution:

According to Newton's second law of motion:

 Force  = mass x acceleration;

 So;

          Mass  = [tex]\frac{force }{acceleration}[/tex]  

          Mass  = [tex]\frac{100}{5}[/tex]   = 20kg

Answer:

or whatever then look it up it

Explanation:

Answer:

Explanation:

Answer:

Lemon slices is the correct answer

Answer:

food coloring

Explanation:

i think food coloring is because it's just water with food coloring and that's it

Answer:

Solids

Is this what your looking for, It might tell you the answer?

Answer:

The entry level is the basic part of any text or power point which needs to be pushed to the higher levels for reading the entire content

Answer:

The value is  [tex]k = 51.34 \ N/ m[/tex]

Explanation:

From the question we are told that

   The  mass is  [tex]m = 1.3 \ kg[/tex]

   The needed oscillation time is  [tex]T = 1 \ s[/tex]  

 Generally the spring constant is mathematically represented  as

         [tex]k = \frac{4 \pi^2 * m }{ T^2}[/tex]

=>      [tex]k = \frac{4* 3.142^2 * 1.3 }{ 1^2}[/tex]

=>      [tex]k = 51.34 \ N/ m[/tex]

Answer:

   ω = ω₀ + α t

      ω² = ω₀² + 2 α  θ

      θ = θ₀ + ω₀ t + ½ α t²

Explanation:

Rotational kinematics can be treated as equivalent to linear kinematics, for this change the displacement will change to the angular displacement, the velocity to the angular velocity and the acceleration to the angular relation, that is

     x → θ

     v → ω

     a → α

with these changes the three linear kinematics relations change to

      ω = ω₀ + α t

      ω² = ω₀² + 2 α  θ

      θ = θ₀ + ω₀ t + ½ α t²

where it should be clarified that to use these equations the angles must be measured in radians

Answer: 1.88 m/s

Explanation:

The speed of the boy moving around a circular park of radius 6 m and taking time 20 seconds is 1.88 m/s.

Speed is a measurement of how quickly an object's distance traveled changes. Speed is a scalar, which implies it has magnitude but no direction as a unit of measurement.

A thing that moves quickly and with great speed, covering a lot of ground in a short time. On the other hand, a slow-moving object traveling at a low speed covers a comparatively small distance in the same amount of time.

Given information:

The radius of the circular park, r = 6 m,

The time is taken to cover one round, t = 20s,

The total distance covered by the boy is equal to the circumference of the park, so

d = 2[tex]\pi[/tex]r,

[tex]d = 2*3.14*6\\d = 37.68 m[/tex]

Now,

the speed of the boy, s = [tex]37.68/20[/tex] ,

s = 1.88 m/s

Therefore, the speed of the boy moving around a circular park of radius 6 m and taking time 20 seconds is 1.88 m/s.

To know more about speed:

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#SPJ2

Answer:

[tex]a_{c} = 13.46\ m/s^2[/tex]

Explanation:

The motion of the tethered ball around the pole can be modeled as uniform circular motion. The acceleration of the objects executing uniform circular motion is due to the change in direction of their velocity. This is called centripetal acceleration. It is given by the following formula:

[tex]a_{c} = \frac{v^2}{r}[/tex]

where,

ac = centripetal acceleration = ?

v = speed of ball = 3.5 m/s

r = distance of ball from center of rotation = 0.91 m

Using these values in equation, we get:

[tex]a_{c} = \frac{(3.5\ m/s)^2}{0.91\ m}\\\\a_{c} = 13.46\ m/s^2[/tex]

Answer:

6.8 m/s

Explanation:

To solve this, we would use the Doppler's Effect. Doppler's effect is represented by the formula

f = [(g + vr)/(g + vs)].fo, where

f = observed frequency, 408 Hz

g = speed of sound in air, 340 m/s

vr = velocity of the receiver

vs = velocity of the source, 0 m/s

fo = source frequency, 400 Hz

Now, applying the values to the equation, we have

408 = [(340 + vr)/(340 + 0) * 400

408/400 = (340 + vr)/340

1.02 * 340 = 340 + vr

346.8 = 340 + vr

vr = 346.8 - 340

vr = 6.8 m/s

Therefore the speed at which the boy is riding his bicycle towards the wall is 6.8 m/s

Answer:

The value is [tex]E = 1.35 *10^{14} \ J[/tex]

Explanation:

From the question we are told that

    The mass of matter converted to energy on first test is  [tex]m = 1 \ g = 0.001 \ kg[/tex]

    The mass of matter converted to energy on second test [tex]m_1 = 1.5 \ g = 1.5 *10^{-3} \ kg[/tex]

    Generally the amount of energy that was released by  the explosion is  mathematically  represented as  

         [tex]E = m * c^2[/tex]

=>       [tex]E = 1.5 *10^{-3} * [ 3.0 *10^{8}]^2[/tex]

=>       [tex]E = 1.35 *10^{14} \ J[/tex]