what is the function of brushes in D.C motor​

Answers

Answer 1

Answer:

to transfer the voltage

Explanation:

The brushes make physical contact with the commutator. When a DC voltage is applied to the brushes, that voltage is transferred into the commutator which, in turn, powers the windings. This electrical input generates a magnetic field around the armature.


Related Questions

A football player at practice pushes a 80 kg blocking sled across the field at a constant speed. The coefficient of kinetic friction between the grass and the sled is 0.30. How much force must he apply to the sled

Answers

Answer:

The value is  [tex]F = 235.2 \ N[/tex]

Explanation:

From the question we are told that

   The mass of the sled is  [tex]m = 80 \ kg[/tex]

  The  coefficient of friction is  [tex]\mu = 0.30[/tex]

Generally the force that must be applied to the sled is equal to the frictional force experienced by the sled which is mathematically represented as

       [tex]F = m * \mu * g[/tex]

=>    [tex]F = 80 * 0.30 * 9.8[/tex]

=>    [tex]F = 235.2 \ N[/tex]

Under what circumstances will the projectile have the greatest velocity when it hits the ground? Explain please

Answers

It will have it’s greatest velocity right before the projectile hits the ground. At the instant it makes contact it become zero and the displacement changes to an upward direction rather than down

a solid sphere and a hollow sphere having same destiny and radius are rolling down an inclined plane. which one of them will reach first ?​

Answers

Answer:

The solid sphere.

Explanation:

The moment of inertia for hollow sphere is larger, thereby having a greater resistance to motion. Thus the solid sphere will have greater speed.

Answer:

The solid sphere

Explanation:

So when comparing the spheres, both spheres have the same density and have the same radius which would they are the same size so the only factor to vary them is mass. The solid sphere is filled and thus heavier compared to the hollow sphere which has lighter air. As a result, the solid sphere will be pulled down by gravity more and reach the bottom first.

25 points and i will give brainliest +5 star rating to a correct a correct answer!!!!

Green light (520 nm) enters glass with n = 1.52. What is speed of light in the glass?

Answers

Answer:

1.97 * 10^8 m/s

Explanation:

Given that:

n = 1.52

Recall : speed of light (c) = 3 * 10^8 m/s

Speed (v) of light in glass:

v = speed of light / n

v = (3 * 10^8) / 1.52

v = 1.9736 * 10^8

Hence, speed of light in glass :

v = 1.97 * 10^8 m/s

Many large and small rocks are found under glaciers. Explain how these rocks are both weathered and eroded.

Answers

Answer:

Explanation below

Explanation:

Ice, mostly in the form of glaciers can create different landforms as it erodes the earth. In some areas with mountains, the glaciers move gradually downhill and across the land areas. When they move, the transport virtually everything on their path, ranging from small grains of sands to huge boulders.  

As these glaciers flow, the rocks being carried in the process scrape against the ground and erode both the ground and the rocks. Rocks are being ground up and oils are scrapped away.  

The main types of erosion created by the glaciers are abrasion and plucking.  

 

The chart below lists the densities of various gemstones. If a gemstone has a mass of 6.24 g and a volume of 1.98 cm cubed, which gemstone is it

A. Opal
B. Diamond
C. Garnet
D. Topaz

Answers

Answer:

C. Garnet

Explanation:

density = mass/volume

density = 6.24g/1.98cm^3

density = 3.15 g/cm^3 (Garnet)

Hope this helps!

Garnets are minerals that can be found as single crystals, pebble-like formations, or masses of intergrown crystals.They are opaque, transparent to translucent minerals. Thus, option C is correct.

What are the physical properties of Garnet?

A garnet has a volume of 1.6 cubic centimetres and a density of 3.5 grams per cubic centimetre. The proportion of a mineral's mass to volume is known as density. It is a measurement of how much “stuff” can fit into the space a mineral takes up.

Garnets can be found in a variety of colours, including orange, yellow, green, purple, brown, blue, black, pink, and colorless, but are most usually found in reddish tones.There are very few blue garnets.

Therefore, density = mass/volume density = 6.24g/1.98 cm^3 density = 3.15 g/cm^3 (Garnet).

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A pinball bangs against a bumper of a pinball machine with a speed of 0.46 m/s. If the ball has a mass of 0.058 kg, what is the ball's kinetic energy?


This needs to be done in 3 mins

Answers

Answer:

Okay I might be wrong and sorry if i am either its 12 or 0.402

Explanation:

* I recommend the second one cause its more logical

Be aware I might be wrong

Any force that resists motion and causes heat

Answers

Answer: Two objects sliding against each other.

Explanation:

The friction between the two surfaces converts kinetic energy into heat.

A mosquito can fly with a speed of 1.10 m/s with respect to the air. Suppose a mosquito flies east at this speed across a swamp. The mosquito is flying into a breeze that has a velocity of 1.4 m/s with respect to Earth and moves in the direction of 35 west of south. What is the mosquito's speed with respect to the Earth?

Answers

Answer:

The velocity of Mosquito with respect to earth will be 0.302m/s

Explanation:

V(ma) = 1.10 m/s, east  Velocity of mosquito with respect to air

V(ae) = 1.4 m/s at 35°  Velocity of air with respect to Earth in west of south direction.

Velocity of Mosquito with respect to earth will be  

V(me) = V(ma) + V(ae)

We need to find the mosquito’s speed with respect to Earth in the x direction.

V(x, me) = V(x, ma) + V(x, ae) = V(ma) + V(ae)(cos theta(ae) )

Angle (ae) = –90.0° − 35°=−125°

V(x, me) = 1.10 + (1.4)Cos(-125)

             = 1.10 + 1.4(-0.57)

             = 1.10 -0.798

              = 0.302

So the velocity of Mosquito with respect to earth will be 0.302m/s

Calculate the mass of a man jogging north along the highway at a rate of 2.65 m/s and a momentum of 225.3 kg*m/s

Answers

Answer:

85.02 kg

Explanation:

The mass of the man can be found by using the formula

[tex]m = \frac{p}{v} \\ [/tex]

v is the velocity

p is the momentum

From the question we have

[tex]m = \frac{225.3}{2.65} \\ = 85.01886...[/tex]

We have the final answer as

85.02 kg

Hope this helps you

The main difference between distance and displacement is tat

Answers

Answer:

Distance is the length of the path taken by an object whereas displacement is the simply the distance between where the object started and where it ended up.

Explanation:

Hope this helps! Good Luck on the rest of your assignments! :)

Answer:

Distance is quite literally the total amount of distance you have covered. Displacement is the total displacement from your origin. For example, if you were to move 5m north then 2m south, your total displacement from your origin would be 3m north.

A block and tackle consisting of 5 pulleys is used to raised a load of 400N through a height of 10m.If the work done against friction is 100j.
Calculate;
1)The work done by the effort
2)The efficiency of the system
3)The effort applied​

Answers

Answer:

1) 4000Joules

2) 25%

3) 320N

Explanation:

A block and tackle consisting of 5 pulleys is used to raised a load of 400N through a height of 10m.If the work done against friction is 100j.

Calculate;

1)The work done by the effort

2)The efficiency of the system

3)The effort applied

1) Workdone by the effort is the work input = Load * distance moved by the Load

Workdone by the effort = 400 * 10

Workdone by the effort = 4000Joules

2) Efficiency = Work output/Work input * 100

Work output = work done against friction = 100 Joules

Efficiency = 100/4000 * 100

Efficiency = 10000/4000

Efficiency  = 25%

Hence the Efficiency of the system is 25%

3) Using the efficiency formula:

efficiency = MA/VR * 100

Velocity ratio = 5

MA = Load/Effort

efficiency = (L/E)/5 * 100

25 = 400/E/5 * 100

25/100 = 400/5E

0.25 = 400/5E

0.25 * 5E = 400

1.25E = 400

E = 400/1.25

E = 320N

hence the effort applies is 320N

A runner exerts a net force of 335 n to accelerate at a rate of 2.5 m/s what is the runners mass

Answers

F=ma
M=F/a
M=335/2.5
M=134 kg

How cold is it in texas rn?

Answers

Answer:

cold

Explanation:

A merry go round exerts a force of 1000 N on a rider on the
outer ring of animals when it takes 15 seconds to make a
complete revolution. If the person weighs 750 N, the radius
of the circle he is making is m. Round your answer to
the nearest tenth.

Answers

Answer:

The radius of the circle made by the person on the merry go round is 74.55 meters

Explanation:

The given parameters are;

The force the merry go round exerts on the rider = 1000 N

The time it takes the merry go round to make one complete revolution = 15 seconds

The weight of the person = 750 N

The radius of the circle made by the person on the merry go round = r

We have;

[tex]F_c = \dfrac{m \cdot v^2}{r} = m \cdot \omega ^2 \cdot r[/tex]

Where;

m = The mass of the person

v = The velocity of the person

[tex]F_c[/tex] = The centrifugal force acting on the person = 1,000 N

r = The radius of the circle made by the person on the merry go round

ω = Angular velocity = 2·π/15 rad/s

We have;

The mass of the person = The weight/(The acceleration due to gravity, g)

∴ The mass of the person = 750/9.81 ≈ 76.45 kg

By substituting the calculated and known values into the equation for  the centripetal force, we have;

[tex]F_c[/tex] = m × ω² × r

1000 = 76.45 × (2·π/15)² × r

r = 1000/(76.45 × (2·π/15)²) = 74.55 m

The radius of the circle made by the person on the merry go round = r = 74.55 m.

plzzzz help me will mark u brainiest

Answers

Answer:

D

Explanation:

Please answer ASAP!!!! Which statement describes the factors that affect the force of a spring?
A. The spring force depends on the spring constant, and increases as displacement
increases
B. The spring force only depends on the spring constant
C. The spring force gets weaker as displacement increases, and is in the same
direction as the displacement
D. The spring force depends on gravity and friction

Answers

Answer:

d

Explanation:

the spring depends on gravity and friction

What is 2 + 2 i have been stuff on this for weeks

Answers

Answer:

4..... the answer is 4

Explanation:

According to my calculations, ummm 67-5272^57x(63838)-927393.738-537363x=3.9

The answer is 3.91


Please give me brainliest!!!!
Lol

the ocean contains many plants and protists that can make their own food through photosynthesis. Which need do these organisms get by living near the surface that they cannot get in deep water?
shelter
oxygen
sunlight

Answers

Answer:

sunlight

Explanation:

Photosynthesis is made possible by energy from the sun.

Who was the first person to study polarization of light?
-Huygens
-Newton
-Galileo
-Copernicus

Answers

Answer:

HUYGENS, CAN I S HAVE BRAINLIST?

Answer:

None

Explanation:

It is erasmus bartholinus

Which statement best explains why Earth’s outer core is in liquid form? The iron-nickel alloy melts due to hot temperatures. The outer core has a tarry consistency. This region is less dense when compared to the mantle. This region is under extreme pressure from the weight of other layers.

Answers

Answer:

I took the science quiz and Its A

Explanation:

HOPE THIS HELPS!

The iron-nickel alloy melts due to hot temperatures. This statement best explains why Earth’s outer core is in liquid form

Where is the outer core?

The Earth's outer core is the second innermost layer, located between the inner core and the mantle. It contains mostly iron and nickel, which- due to lower pressure than existing at the inner core- are in the liquid form. The outer core, about 2,200 kilometers (1,367 miles) thick, is mostly composed of liquid iron and nickel  because of the high temperature. However, the intense pressure, which increases towards the inner core, dramatically changes the melting point of the nickel–iron, making it solid. The  iron and nickel alloy of the outer core is very hot, between 4,500° and 5,500° Celsius (8,132° and 9,932° Fahrenheit).

The outer core is a liquid alloy of mainly iron and nickel. The reason why the core is metal is that the heavy metals sank to the center while the Earth was cooling. The mantle which lies above the core is made of molten rock

correct option is a) The iron-nickel alloy melts due to hot temperatures.

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12. The diameter of a circle is 2.42m. Calculate its
area in proper significant figure​

Answers

Answer:

A = 4.6 [m²]

Explanation:

The area of a circle can be calculated by means of the following equation.

[tex]A=\frac{\pi }{4} *D^{2}[/tex]

where:

A = area [m²]

D = diameter = 2.42 [m]

Now replacing:

[tex]A=\frac{\pi }{4} *(2.42)^{2} \\A = 4.6 [m^{2} ][/tex]

A boy throws a stone vertically in the air with an initial speed of 40m/sec.At the instant the stone is thrown,a monkey at the top of a tree h m high falls freely.How long will it take for the stone to hit the monkey if they meet at a point mid way between the ground and the top of tree?

Answers

∞infinaty stones∞

because why not

5) A 20.0 kg cart with no friction wheels sits on a table. A light string is attached to it and runs over a low friction pulley to a 0.0150 kg mass.

Draw a free body diagram showing all the forces acting on each object
Calculate the acceleration of the masses
Calculate the tension force in the cord
How long will it take the block to get to go 1.2 m to the edge of the table.
What will the velocity be as soon as it gets to the edge?

Answers

Answer:

1) Please find attached, created with Microsoft Visio

2) The acceleration of the masses connected by the light string is 0.00735 m/s²

3) The tension in the cord is 0.147 N

4) The time it would take the block to go 1.2 m to the edge of the table is approximately 18.07 s

5) The velocity of the cart as soon as it gets to the edge of the table is 0.042 m/s

Explanation:

1) Please find attached, the required free body diagram, showing the tension, weight and frictional (zero friction) forces acting on the cart and the mass created with Microsoft Visio

2) The acceleration of the masses connected by the light string is given as follows;

F = Mass, m × Acceleration, a

The mass of the truck, M = 20.0 kg

The mass attached to the string, hanging rom the pulley, m = 0.0150 kg

The force, F acting on the system = The pulling force on the cart = The tension on the cable = The weight of the hanging mass = 0.0150 × 9.8 = 0.147 N

The pulling force acting on the cart, F = M × a

∴ F = 0.147 N = 20.0 kg × a

a = 0.147 N/(20.0 kg) = 0.00735 m/s²

The acceleration of the truck = a = 0.00735 m/s²

3) The tension in the cord = F = 0.147 N

4) The time, t, it would take the block to go 1.2 m to the edge of the table is given by the kinematic equation, s = u·t + 1/2·a·t²

Where;

s = The distance to the edge of the table = 1.2 m

u = The initial velocity = 0 m/s (The cart is assumed to be initially at rest)

a = The acceleration of the cart = 0.00735 m/s²

t = The time taken

Substituting the known values, gives;

s = u·t + 1/2·a·t²

1.2 = 0 × t + 1/2 ×0.00735 × t²

1.2 = 1/2 ×0.00735 × t²

t² = 1.2/(1/2 ×0.00735) ≈ 326.5306

t = √(1.2/(1/2 ×0.00735)) ≈ 18.07

The time it would take the block to go 1.2 m to the edge of the table = t ≈ 18.07 s

5) The velocity, v, of the cart as soon as it gets to the edge of the table is given by the kinematic equation, v² = u² + 2·a·s as follows;

v² = u² + 2·a·s

u = 0 m/s

v² = 0² + 2 × 0.00735 × 1.2 = 0.001764

v = √(0.001764) = 0.042

The velocity of the cart as soon as it gets to the edge of the table = v = 0.042 m/s.

Answer:

There's no answer I'm just taking points like you did me,  so thank you for your points I'll put them to good use ;)

HELP! WILL GIVE BRAINLIST!!!
- How do the greenhouse gases warm the atmosphere?
a. Solar radiation penetrates the atmosphere and is trapped by greenhouse gases which warms the atmosphere.
b. Solar radiation is absorbed by the Earth which directly warms the atmosphere.
c. Infrared radiation from the Sun is trapped by greenhouses gases and heats the atmosphere.
d. Solar radiation absorbed by the Earth is converted to infrared which is blocked by greenhouse gases and heats the atmosphere.

Answers

Answer:

Explanation:

Option C is the correct answer

Infrared radiation from the Sun is trapped by greenhouse gases and heats the atmosphere, by this phenomenon of heat absorption the greenhouse gases warm the atmosphere,therefore the correct answer is option C.

What is electromagnetic radiation?

The propagation of electromagnetic waves, which are generated from both natural and artificial sources, results in the energy radiation known as electromagnetic radiation.

This radiation does not need any kind of medium to propagate. The electromagnetic wave has components of light as well as heat in them.

By absorbing heat through the process of heat assimilation, greenhouse gases warm the atmosphere by trapping infrared light from the Sun.

Thus, the correct answer is option C.

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Electricity from the local power company costs 5.79 cents/kWh. How much would it cost to run a 120-W stereo system for 4.0 hours per day for 4.0 weeks?

A. $1.33

B. $0.78

C. $0.11

D. $2.18

Answers

Answer:

Answer: B. $0.78.

Explanation:

Cost of Electricity

The rate of the cost of electricity is usually expressed in $/kWh or cents/kWh because the consumption of electricity is measured in Kilowatts-hour.

The local power company charges 5.79 cents/kWh.

We are required to calculate the cost to run a 120 W stereo system for 4 hours per day for 4 weeks.

The total consumption time is 4 hours/day * 7 days/week *4 weeks = 112 hours

The total energy consumed is 120 W * 112 h =13,440 Wh.

Converting to kWh: 13,440 Wh/1,000 = 13.440 kWh.

Finally, we multiply by the cost rate: 5.79 cents/kWh * 13.440 kWh = 77.8 cents/100 = $0.78.

Answer: B. $0.78.

Which of the following does not illustrate a complete circuit?

Answers

Answer:

I think A

Explanation:

because it dosn't have enough tools

Laws of motion




Laws of motion





Answers

Answer:

Newton's laws of motion are three physical laws that, together, laid the foundation for classical mechanics. They describe the relationship between a body and the forces acting upon it, and its motion in response to those forces.

Explanation:

What are Newton's 1st 2nd and 3rd laws of motion?

In the first law, an object will not change its motion unless a force acts on it. In the second law, the force on an object is equal to its mass times its acceleration. In the third law, when two objects interact, they apply forces to each other of equal magnitude and opposite direction.

A bus accelerates forward. If an apple were on the floor of the bus it would move forward.
A: True
B: False

Answers

Answer:

False

Explanation:

Since it is on the bus, it would not move forward because the outside acceleration cannot be considered.

Do you think the inner planets should be explored or should the money be spent on other things? Justify your opinion.

Answers

Answer:

yes i think that inner planets should be explored because if we ever find new life or are able to live there then i think its worth takeing a risk.

Explanation:

Other Questions
The Dead Sea, which lies between Jordan and Israel, is one of the saltiest lakes on Earth. Suppose you are a geologist exploring the area. What geological factors would you expect to see that might explain this salinity 5 + 0.08 + 0.004 in word form plz subject and verb for the fish was to small to keep On average, an adult male sea otter weighs 36 kg (79 pounds), with some individuals weighing as much as 45 kg (99 pounds). A female weighs an average of 23 kg (50 pounds). To maintain their weight, otters must consume 250 kilocalories/kg of body weight each day to survive. Otters eat almost entirely small invertebrates for which they must dive to catch.You have been tracking an adult female otter who weighs 25 kg. Answer the following questions based on the data provided.How many kilocalories must she consume each day to maintain her body weight?Question options:6,250 Kcals275 Kcals1,620 Kcals9,000 Kcals Why weren't canoes used in the arctic region?Air and water were too strong.Air and water were too cold.o Only one person ever went fishing.o They were too heavy to lift. Which detail supports the idea that robots will not take over medical jobs? a) robots can figure out what is wrong with patients faster than humans can.b) robots cannot have the relationship with the patients that doctors have.c) robots do not need to take vacations or get paid any money like people do.d) robots do not get distracted like human nurses and doctors do. how does the immune system uses feedback mechanisms? A) 41 cm2B) 54 cm2C)81 cm2D)121.5 cm2 what is the meaning of paradigm? Please answer! solve for x i been needing help with my work on study island HELP ME PLS WITH THIS 4Select the correct answer.Jessica wants to find more information about the effects of sports on the mental health of teenage girls. What would be a good primary sourcefor Jessica to use?a research article that includes interviews with teenage athletes.an op-ed from a teacher discussing depression in teenage girls. .an interview with a psychologist who specializes in working with teen athletesOD.a biography of a famous athlete who mentors young athletesResetNext what is fast,loud and crunchy?.. what is the total magnification of a microscope with an eyepiece magnification of 10x and an objective lens magnification of 50x quizziz What is the proper role of government in the economy? Rachel is buying school supplies. She needs to buy a binder for $4.50, whiteboard markers for $7.00 and some mechanical pencils for $0.29 each. She can spend up to $13.00. Which inequality can be used to find m, the number of mechanical pencils she can buy? Determine if the statement is true or false.The attempted assassination of President Teddy Roosevelt caused so much public outrage that the insanity defense was greatly restricted. Felixs Feed Mill sells chicken feed for $8.00 per bag. This price is no longer high enough to create a profit. Felix decides to raise the price. He is considering four different plans.Plan A: Raise the price by $0.10 each week until the price reaches $12.00.Plan B: Raise the price by 10 percent each week until the price reaches $12.00.Plan C: Raise the price by the same amount each week for 8 weeks, so that in the eighth week the price is $12.00.Plan D: Raise the price by $0.25 each week until the price reaches $12.00.Which plan will result in the price of the feed reaching $12.00 fastest?-plan A-plan B-plan C-plan D BRAINLIEST TYSMexplain the vents that led to the reunification of east and west germany in the 1990s. what makes this region a historically significant part of this era? in addition discuss how the reunification of germany led to economic problems. explain why these changes were inevitable