What best describes a bar magnet

Answers

Answer 1

Answer:Bar magnets are permanent magnets as opposed to electromagnets

Answer 2

Answer Expert Verified
Bar magnets are permanent magnets as opposed to electromagnets. While electromagnets require electric current to be magnetised, and so they can be turned on and turn off, bar magnets are made of magnetic materials and have two poles which cannot be turned

Related Questions

The magnetic dipole moment of Earth has magnitude 8.00 × 1022 J/T. Assume that this is produced by charges flowing in Earth's molten outer core. If the radius of their circular path is 3470 km, calculate the current they produce

Answers

Answer:

Explanation:

Dipole moment of a coil carrying current i with area A

M = i A , M is magnetic moment , i is current and A is area of the coil.

A = π R²

= 3.14 x ( 3470 x 10³ )²

= 3.78 x 10¹³  m²

8.00 x 10²² = 3.78 x 10¹³ x i

current i = 8.00 x 10²²  / 3.78 x 10¹³

= 2.11 x 10⁹ A .

A solid sphere, with a mass of 3 kg, is rolling across a horizontal floor without slipping. The sphere has 8.4 J of total kinetic energy and has a center of mass velocity of 2 m/s. Calculate the rotational kinetic energy of the solid sphere.

Answers

Answer:

2.4 J

Explanation:

The total kinetic energy of the solid sphere = rotational kinetic energy + translational kinetic energy

KE(total) = KE(rot) + KE(trans)

KE(rot) = KE(total) - KE(trans)

Since its total kinetic energy KE' = 8.4 J and its mass, m = 3 kg and the velocity of its center of mass, v = 2m/s, KE(trans) = 1/2mv² = 1/2 × 3 kg × (2 m/s)² = 3 kg × 2 m²/s² = 6 kgm²/s² = 6 J

So, KE(rot) = KE(total) - KE(trans)

Substituting the values of the variables, we have

KE(rot) = 8.4 J - 6 J

KE(rot) = 2.4 J

So, the rotational kinetic energy of the solid sphere is 2.4 J

The rotational kinetic energy of the solid sphere will be "2.4 J".

Kinetic energy

According to the question,

Total Kinetic energy, KE' = 8.4 J

Mass, m  = 3 kg

Center of mass's velocity, v = 2 m/s

Now,

KE(trans) = [tex]\frac{1}{2}[/tex]mv²

By substituting the values,

               = [tex]\frac{1}{2}[/tex]  × 3 × (2)²

               = [tex]\frac{1}{2}[/tex] × 3 × 4

               = 6 kgm³/s² or,

               = 6 J  

We know the relation,

→ KE(rot) = KE(total) - KE(trans)

By putting the values,

              = 8.4 - 6

              = 2.4 J

Thus the approach above is correct.  

Find out more information about kinetic energy here:

https://brainly.com/question/25959744

A 11.8-kg cylinder rolls without slipping on a rough surface. At an instant when its center of gravity has a speed of 10.4 m/s, determine the following. (a) the translational kinetic energy of its center of gravity J (b) the rotational kinetic energy about its center of gravity J (c) its total kinetic energy J

Answers

Answer:

1. 638.144j

2. 319.072 j

3. 957.216 j

Explanation:

M = 11.8 kg cylinder

V = speed of center of gravity = 10.4m/s

A.

Translational kinetic energy

= 1/2mv²

1/2x 11.8kg x 10.4²

= 11.8x108.16/2

= 1276.288/2

= 638.144 J

This is the translational energy

B.

Rotational energy

1/2Iw²

I = mv²/2

w = v/r

When we substitute

1/2[mv²/2][v/r]²

= 1/4mv²

= 1/4 x 11.8 x 10.4²

= 1276.288/4

= 319.072

This is the rotational energy

C

Total kinetic energy.

We add the values of A and B above to get this.

638.144 J + 319.072 J

= 957.216J

How much time is required for an airplane to reach its takeoff speed of 77m/a if it starts from rest and its average acceleration is 8.2m/s^2?

Answers

Answer:

The time required is t = 9.39 [s]

Explanation:

To solve this problem we must use the following equation of kinematics.

[tex]v_{f}=v_{o} +(a*t)[/tex]

where:

Vf = final velocity = 77 [m/s]

Vo = initial velocity = 0

a = acceleration = 8.2 [m/s²]

t = time [s]

The initial speed is zero, since the airplane begins its movement from rest. The initial speed is zero, since the aircraft begins its movement from rest. Another important fact is that the sign of acceleration is positive since the plane is accelerating, that is, its speed is increasing.

Now replacing:

77 = 0 + (8.2*t)

t = 9.39 [s]

how much kinetic energy does a 2,000 kg car have when its traveling 5 m/s

Answers

Answer: 5000J

Explanation:

equation for kinetic energy is k=(mv^2)/2

plug in your mass and velocity

k = (2000*5^2)/2 = 5000J

What role do planetesimals play in the origin of the planets?

Answers

A planetesimal is small bodies from which a planet originated in the early stages of formation of the solar system. Protoplanets are when planetesimals join together through collisions and through the force of gravity to form larger bodies. ... Because they have their gases they are not as dense as the inner planets.

A woman runs up a flight of stairs. The gain in her gravitational potential energy is U. If she runs up the same stairs with twice the speed, what is her gain in potential energy?

Answers

Answer:

U

Explanation:

The change in gravitational potential energy only depends of the difference in height (in this case the number of stairs), so as the height remained the same, her gain in potential energy remained the same, independent from her climbing speed.

You can't always see electromagnetic waves, but they are found throughout
the universe. There are only a few waves that are visible to the human eye.
Electromagnetic radiation is used to meet our needs and wants. It makes
important things — like medical imaging, reheating food and cell phones
possible. Radiation can be helpful for sending texts, but it's not always a
good thing. The sunburn you get sitting on the beach is caused by
electromagnetic radiation, too.
The author of this passage would most likely agree with which of the following
statements?
A
Scientists do not know very much about electromagnetic waves.
B
Electromagnetic radiation can be both helpful and harmful to humans.
с
People understand electromagnetic waves better than ocean waves.
D
Electromagnetic radiation is more harmful than it is helpful.

Answers

The answer to the question is D.

The author of this passage is focusing on both the merits and demerits of electromagnetic waves. Thus, he agree with the statement  that electromagnetic radiation can be both helpful and harmful to humans.

What are electromagnetic waves?

Electromagnetic waves are transformation of energy and they are travelling with a combined electric field and magnetic field. There are various kinds of electromagnetic waves namely, ultraviolet, radio waves, microwaves x-rays etc.

All these waves have significant applications in various fields. Mostly in medical fields. They are used for diagnosing, cancer treatments drug optimization etc.

However, these waves are highly energetic and harmful too. Direct and elongated exposure to these waves may cause severe health risks including cancer.

The author addresses the advantages and disadvantages of the electromagnetic waves. Thus, option B is correct.

To find more on electromagnetic waves, refer here:

https://brainly.com/question/3101711

#SPJ2

How many atoms of each element are
needed to bond
Ca + F
k+ S
Li+ O

Answers

Answer:

How many electrons whill each element gain or lose in forming an ion? ... to form an ionic compound? a. Al and O b. H and N c. I and K d. F and Cl e. Li and S ... free flowing, but the valence electrons in ionic crystals have a strong bond with their atoms ... necessary to attain the electron configuration of what kind of element

Explanation:

Anybody good at science math?

Answers

Answer:

the pressure is: 200 N/m^2

Explanation:

Recall that pressure is defined as force (F) per unit of area (A), which in math terms is:

P = F / A

Then, if the force is 2.4 N , and the area of the glass' bottom is 0.012 m^2, then the pressure is:

P = 2.4 / 0.012 = 200 N/m^2

Answer:PLEASE HELP ME

Explanation:

25 POINTS FIRST CORRECT GET BRAINLIEST!!!!!!!!!!!!!!!!1

Answers

Answer:

carbon isnt 12

Explanation:

Starting from rest, a 94-kg firefighter slides down a fire pole. The average frictional force exerted on him by the pole has a magnitude of 750 N, and his speed at the bottom of the pole is 3.1 m/s. How far did he slide down the pole

Answers

Given that,

Mass of a firefighter, m = 94 kg

Frictional force, F = 750 N

Speed at the bottom of the pole is 3.1 m/s

It is required to find the distance he slide down the pole.

Using Work-energy theorem,

initial potential energy = final kinetic energy + work done

[tex]mgh=W+\dfrac{1}{2}mv^2[/tex]

[tex]mgh=Fh+\dfrac{1}{2}mv^2[/tex]

Solving for h, such that :

[tex]h(mg-F)=\dfrac{1}{2}mv^2\\\\h=\dfrac{1}{2(mg-F)}mv^2\\\\h=\dfrac{1}{2(94(9.8)-750)}\times 94\times (3.1)^2\\\\h=2.63\ m[/tex]

So, he will slide 2.63 m down the pole.

Problem 9.20 A sphere of uniform density with mass 18 kg and radius 0.8 m is spinning, making one complete revolution every 0.4 s. The center of mass of the sphere has a speed of 8 m/s. (a) What is the rotational kinetic energy of the sphere

Answers

Answer:

K = 567.91 J

Explanation:

Given that,

Mass of sphere, m = 18 kg

Radius of a sphere, r = 0.8 m

It makes one complete revolution every 0.4 s.

The speed of center of mass of the sphere is 8 m/s

We need to find the rotational kinetic energy of the sphere. It is given by the formula as follows :

[tex]K=\dfrac{1}{2}I\omega^2[/tex]

I is moment of inertia,

[tex]I=\dfrac{2}{5}mr^2\\\\I=\dfrac{2}{5}\times 18\times (0.8)^2\\\\I=4.608\ kg-m^2[/tex]

[tex]\omega[/tex] is angular speed

[tex]\omega=\dfrac{2\pi }{0.4}\\\\=15.7\ rad/s[/tex]

So,

[tex]K=\dfrac{1}{2}\times 4.608\times (15.7)^2\\\\K=567.91\ J[/tex]

So, the rotational kinetic energy of the sphere is 567.91 J.

The rotational kinetic energy of the sphere is 710.8 J.

Moment of inertia of the sphere

I = ¹/₂mr²

I = 0.5 x 18 x (0.8)²

I = 5.76 kgm²

Angular speed of the sphere

ω = 2πf

ω = 2π x (1/0.4s)

ω = 15.71 rad/s

Rotational kinetic energy

K.E = ¹/₂Iω²

K.E = 0.5 x (5.76) x (15.71)²

K.E = 710.8 J

Thus, the rotational kinetic energy of the sphere is 710.8 J.

Learn more about rotational kinetic energy here: https://brainly.com/question/25803184

what is it? and explain pls

Answers

The velocity at which an object is sent moving and the mass of the object both play a hand in the level of kinetic energy that object produces. Mass and kinetic energy have a positive relationship, which means that as mass increases, kinetic energy increases, if all other factors are held constant.

11.
A current of 67 amps runs through a resistor of 37 ohms, how much voltage is lost?

Answers

You divide them. 67/37 is 1.5 and so you subtract it with the 67 and multiple it by the coherent integer from the multiplication and you would get 20 volts lost roughly.

Answer: 20 volts

A centrifuge in a medical laboratory rotates at an angular speed of 3,550 rev/min. When switched off, it rotates through 52.0 revolutions before coming to rest. Find the constant angular acceleration (in rad/s2) of the centrifuge.

Answers

Answer:

-62.02πrads/sec^2

Explanation:

A centrifuge in a medical laboratory rotates at an angular speed of 3,550 rev/min. When switched off, it rotates through 52.0 revolutions before coming to rest. Find the constant angular acceleration (in rad/s2) of the centrifuge.

We need to convert to SI unit

9.549rev/ min= 1rad/sec

Then to convert angular speed of 3,550 rev/min to rad/sec

( 1 rad/sec)/9.549rev/min = x/5600rev/min

Then

(3,550 rev/min)/(9.549rev/min)= 371.77rad/sec

=118.4πrad/sec

6.823rad= 1rev

52.0 revolutions = 52×6.823= 354.796rads

= 113πrads

We will use expresion below to calculate our angular acceleration

w^2 - w^2(0)= 2α¢

Where w= angular speed

w(0)= initial angular

If final angular speed= 0

α=-w^2(0)/2¢

α=(-118.4π)^2/(2×113)

=-14018.56/226

-62.02πrads/sec^2

Does heat and temperature depend on the other or are they totally separate ideas? Explain.

Answers

Answer:

What heat means in thermodynamics, and how we can calculate heat using the heat ... Scientists define heat as thermal energy transferred between two systems

Explanation:

thermal energy

what is the average speed of a student 100cm/s Bernard 150 cm/s Chloe 50 cm/s Dev 75 cm/s Eduardo 125cm/s

Answers

Answer:

100cm/s

Explanation:

Given the speed of the following students;

Bernard 150 cm/s

Chloe 50 cm/s

Dev 75 cm/s

Eduardo 125cm/s

Their average speed of a student will be the mean of their individual speed as shown:

Average speed = 150+50+75+125/4

Average speed = 400/4

Average speed = 100

Hence the average speed of a student is 100cm/s

If a coil stays at rest in a very large static magnetic field, no emf is induced in this coil. Group of answer choices True False

Answers

Answer:

True

Explanation:

Faraday's Law says that there is a emf induced in a conductor when the vector flux of the magnetic field across it changes in time.This can be true due to one of two facts, either the magnitude of the magnetic field changes in time, or the area through which the flux occurs changes due to the movement of the object.In this case, due to the magnetic field is constant, and the coil stays at rest, there is no possible change in flux, so emf induced is zero.

For a smooth sphere with a 11 cm diameter thrown through air (air density of 1.25 kg/m3, air viscosity 1.83*10-5 Pa-s), what is the speed (in cm/s) when the Reynolds number is 2,511

Answers

Answer:

u = 0.334 m/s

Explanation:

The formula for Reynold's number is given as follows:

Re = ρuL/μ

where,

Re = Reynold's Number = 2511

ρ = Density of air = 1.25 kg/m³

μ = Dynamic Viscosity of Air = 1.83 x 10⁻⁵ Pa.s

L = Characteristic Length = Diameter of Sphere = 11 cm = 0.11 m

u = Speed = ?

Therefore,

2511 = (1.25 kg/m³)(u)(0.11 m)/(1.83 x 10⁻⁵ Pa.s)

u = (2511)/(7513.66 s/m)

u = 0.334 m/s

Find the electric field due to an infinite plane of positive charge with uniform surface charge density

Answers

Answer:

Explanation:

The Electric field due to an infinite plane of positive charge with uniform surface charge density can be derived a s follows

let us assume An infinite positively charged sheet and lets take a cylindrical gaussian surface on this surface which is perpendicular to this plane of sheet

we know that positive charge electric field lines will be perpendicular to this sheet surface will be perpendicular to the cylindrical surface

applying gauss law

[tex]Electric field * Area =[/tex] [tex]charge/epsilon\\[/tex]

also sigma=Q/A ⇒ Q=sigma*A

so on one face

E*A=sigma*A/epsilon

also we notice this electric field on one face of the sheet is exactly equal to that on the another face hence electric field will be twice

2E*A=sigma*A/epsilon

final result

[tex]E= sigma/2*epsilon[/tex]

Find the terminal velocity of a spherical bacterium (diameter ) falling in water. You will first need to note that the drag force is equal to the weight at terminal velocity. Take the density of the bacterium to be .

Answers

Complete Question

Find the terminal velocity of a spherical bacterium (diameter [tex]2.00 \mu m[/tex] ) falling in water. You will first need to note that the drag force is equal to the weight at terminal velocity. Take the density of the bacterium to be [tex]1.10 *10^{3} \ kg/m^3[/tex]

Answer:

The value is [tex]v_t = 2.38*10^{-6} \ m/s[/tex]

Explanation:

From the question we are told that

   The diameter of the  spherical bacterium is [tex]d = 2.0\mu m = 2.0 *10^{-6} \ m[/tex]

     The density of the bacterium is  [tex]\rho =1.10 *10^{3} \ kg/m^3[/tex]

Generally the radius is mathematically represented as

       [tex]r = \frac{d}{2}[/tex]

=>   [tex]r = \frac{2.0 *10^{-6}}{2}[/tex]

=>   [tex]r = 1.0*10^{-6}[/tex]

Generally the volume is mathematically represented as

     [tex]V = \frac{4}{3} * \pi * r^2[/tex]

=>[tex]V = \frac{4}{3} * 3.142 * (1.0*10^{-6})^3[/tex]

=>[tex]V = 4.189 *10^{-18} \ m^3[/tex]

Generally the mass is mathematically represented as

     [tex]m = V * \rho[/tex]

=>  [tex]m = 4.189 *10^{-12} * 1.10 *10^{3}[/tex]

=>  [tex]m = 4.608 *10^{-15} \ kg[/tex]

Generally the terminal velocity is mathematically represented as

     [tex]v_t = \frac{m * g}{ 6\pi * r * \eta}[/tex]

Here  [tex]\eta[/tex] is the viscosity of water with value  [tex]\eta = 1.005 *10^{-3} \ kg/m\cdot s[/tex]

So

     [tex]v_t = \frac{4.608 *10^{-15} * 9.8}{ 6 * 3.142 *1.0*10^{-6} * 1.005 *10^{-3}}[/tex]

=>  [tex]v_t = 2.38*10^{-6} \ m/s[/tex]

Which atoms are deflected the most by the magnetic field?

Answers

Answer:

Different ions are deflected by the magnetic field by different amounts. The amount of deflection depends on: the mass of the ion. Lighter ions are deflected more than heavier ones.

the weight of a box having a mass of 100kg is blank N.

Answers

Answer:

What is the answer we are supposed to be finding?

Explanation: Your answer is 980.7 if you are converting kilograms to Newtons

The exchange of oxygen and carbon dioxide takes place through the capillary wall.
True
False

Answers

Explanation:

It mainly flows blood to arteries of heart but the answer is true.. because it also exchange oxygen,nutrient etc..

Using five or more sentences, describe petroleum and what it is used for.

(I might mark brainliest if it is a good response) :D

Answers

Answer:

A liquid mixture of hydrocarbons that is present in certain rock strata and can be extracted and refined to produce fuels including gasoline, kerosen, diesal oil. :)

Explanation:

Yea mark brainleist pls

A 10-kg object is hanging by a very light wire in an elevator that is traveling upward. The tension in the rope is measured to be 75 N. What are the magnitude and direction of the acceleration of the elevator

Answers

Answer:

2.31m/s² downwards

Explanation:

The sum of forces on the object is expressed as;

T-W

T is the tension on the rope

W is the weight

According yo Newton's second law:

T-W= ma

m is the mass

a is the acceleration

Given

T = 75N

W = mg = 10×9.81

W = 98.1N

Substitute

75-98.1 = 10a

-23.1 = 10a

a = -23.1/10

a = -2.31m/s²

The magnitude of the acceleration is 2.31m/s² and directions is downwards

Use the drop-down menus to identify the parts of the diagram labeled A, B, and C.

Label A

Label B

Label C

Answers

Answer:

b

Explanation:

bcuz I looked it up and it was on there

Answer:

the answers are:

- cool fluid sinks

- warm fluid rises

- convention current

Explanation:

Im late but mark me as brainliest for helping you out cause the one on top is clueless

A pilot wants to fly north. The plane has an air speed of
350 km/h. There is a 25 km/h wind blowing to the west.
(a) What is the plane's velocity relative to the ground?
(b)What is its heading?

Explain me in details. I’ll give u the brainliest if you give me the right answer.

Answers

Answer:

A? Cause is needs the Velocity more than the Heading.

The spacecraft that have visited the outer planets have all flown close to inner planets (Venus, for example), often more than once, as part of their journeys. What was the primary reason for this?

Answers

Answer:

1) The outer planets happened to have been on the far side of the sun, so the shortest route passes the inner planets

Explanation:

All the planets revolve around the sun in a circular orbital. The orbits of Mercury, Venus, Earth, and Mars are tightly held with sun as they are very close to the sun and revolve faster in comparison to outer planet Jupiter, Saturn, Uranus, and Neptune.

Because of the shortest distance between the sun and inner planets, the spacecraft is able to visit the inner planet more than once while outer planets are very far from the sun and revolve around a large orbit, so the spacecraft visited the outer planets less than the inner planet.

Hence, the correct answer is "1".

Other Questions
fill in the blank for free brainliest. I have so many questions! first of all, how do ______ ____? and how are _____ so _____. ALSO THE BEST QUESION _________________??? How many is (+5) --(692)+1/3% Below is a quotation about the Battle of Thermopylae, during the Persian Wars: One of the Greeks said, "Such was the number of the barbarians, that when they shot forth their arrows the sun would be darkened by their multitude." Dieneces the Spartan, not at all frightened at these words, answered, "Our friend brings us excellent tidings. If the Persians darken the sun, we shall have our fight in the shade." adapted from The Histories, Book 7 Herodotus This quotation is from the point of view of a Greek historian. What does it indicate about the Spartans during this battle? A. The Spartans were willing to fight bravely even if they could not win. B. The Spartans had an advantage against the Persians when fighting at night. C. The Spartans lost against the Persians because they had weaker weapons. D. The Spartans were too proud to cooperate with their Athenian allies. how are the particles in a solid piece of ice organized cultural differences between the Nez Perce and the U.S. government and European-American settlersespecially their beliefs and values? How did William penns city Of Philadelphia influence the development of values and beliefs of the US Constitution plz answer this question of "The Great Train Journey" A person walks 200meters at 27 degrees north of East What is the most logical explanation for why kilo is a more important prefix to remember than tera PLEASE HELP I ONLY HAVE 30 MINUTES!!!!Which elements of an MLA citation appear in italics? Check all that apply.Article titlesbook titlesmagazine titlesnewspaper titlespublishers' nameswebsite names What is the equation of the line x3y=18in slope-intercept form? Briefly explain in a few sentences the differences between how a sunflower gets energy and a squirrel gets energy. Include the words glucose, produces, and consumes in your answer. My mother just said "stand right here honey don't look behind the dumpster where me and jerry are going to be hugging for the next bit ok?" WHAT DOES THAT MEAN?!?!? () Heather is training for a long-distance run. Her data points listed below represent the days of practice, x, and thenumber of miles run, y.(1, 2.5), (2, 4.2), (4,5.6), (6, 7), (8, 8.1), (10, 11)Use the equation to interpolate the value and estimate the distance that she could have run on day 3. Round to thenearest tenth of a mile.milesOday 3 HELP ASAP!! Article three of the U.S. Constitution gives the judicial branch the power to: A country that suffers from a lack of central governmental authority is experiencing __________.A.a theocracyB.a constitutional monarchyC.a monarchyD.anarchy Minor character usually classified as A. Round B. Dynamic C. Static read this excerpt from "The Medicine Bag". Nothning borhered cheryl about bringing her ftiends to see grandpa. Every day after schools started, there'd be a crew of giggling little girls or round-eyed little boy crowded around the old man on the patio, where he'd gotten in the habit of sitting every afternoon. Grandpa would smile in his gentle way and patiently answer their questions, or he'd tell them stories of brave warriors, ghosts, animals; and the kids listened in awed silence. those little guys thought Grandpa was great. which statement best describes a symbol in this excerpt? a. Cheryl is Martin's younger sister. b. Cheryl represents childhood innocence.c. The little kids are curious about Grandpa.d. The little kids represent warriors and ghosts. help please asap lol Three out of 7 students at the dance were boys if 140 students attended the dance how many were girls enter number of girls here ___