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3 years ago

Which is an important step in how an electric motor uses magnetic force to produce motion?

Physics

2 answers:

Usimov [2.4K]3 years ago

6 0

Answer:

B) As the north pole of the electromagnet nears the south pole of the permanent magnet, the current reverses and the poles of the magnets then repel.

Explanation:

As we know that electric motor is based on the concept of torque due to magnetic field on current carrying coil.

Here as the current is passing through the coil the torque on the coil is given as

$\tau = NiAB sin\theta$

so here the magnetic field due to coil will continuously repelling the current carrying coil as it will move between the magnetic field so direction of current in the coil will change continuously so that it will always repel by the magnetic field and continuously rotated between the magnets

Fiesta28 [93]3 years ago

3 0

Answer:B.As the north pole of the electromagnet nears the south pole of the permanent magnet, the current reverses and the poles of the magnets then repel.

Explanation:

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All objects are either ___________ or ___________. Charged objects can have a ____________ or _____________ charge. Uncharged ob

KATRIN_1 [288]

All objects are either charged or uncharged. Charged objects can have a positive or negative charge. Uncharged objects will have a no charge. Charged objects that have the same charges will repel each other. Charged objects with opposite charges will attract each other. Uncharged objects can become charged. The charge an object has gives it electric energy. The charged object’s ability to attract (pull) or repel (push) other objects is called electrostatic force.

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2 years ago

What is the most effective way to clean the science desks? Hypothesis:

lukranit [14]

The most effective way to clean a science desks is to use a soapy water solution to clean tables using a clean disposable paper towel. Second, after cleaning the table surface with soap or detergent and rinsing with water, disinfect tables by using a diluted bleach water solution

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3 years ago

A 10.0 N package of whole wheat flour is suddenly placed on the pan of a scale such as you find in grocery stores. The pan is su

inna [77]

Answer:

0.025 m

Explanation:

From the question,

Applying Hook's law

F = ke................... Equation 1

Where F = Force, k = spring constant of the scale, e = maximum distance at which the spring will compress.

make e the subject of the equation

e = F/k....................... Equation 2

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3 years ago

A block of ice(m = 14.0 kg) with an attached rope is at rest on a frictionless surface. You pull the block with a horizontal for

nadezda [96]

Answer:

a) The weight and the normal force of the block has a magnitude of 137.298 newtons and the pull force exerted on the block has a magnitude of 98 newtons.

b) The final speed of the block of ice is 9.8 meters per second.

Explanation:

a) We need to calculate the weight, normal force from the ground to the block and the pull force. By 3rd Newton's Law we know that normal force is the reaction of the weight of the block of ice on a horizontal.

The weight of the block ( $W$ ), measured in newtons, is:

$W = m\cdot g$ (1)

Where:

$m$ - Mass of the block of ice, measured in kilograms.

$g$ - Gravitational acceleration, measured in meters per square second.

If we know that $m = 14\,kg$ and $g = 9.807\,\frac{m}{s^{2}}$ , the magnitudes of the weight and normal force of the block of ice are, respectively:

$N = W = (14\,kg)\cdot \left(9.807\,\frac{m}{s^{2}} \right)$

$N = W = 137.298\,N$

And the pull force is:

$F_{pull} = 98\,N$

The weight and the normal force of the block has a magnitude of 137.298 newtons and the pull force exerted on the block has a magnitude of 98 newtons.

b) Since the block of ice is on a frictionless surface and pull force is parallel to the direction of motion and uniform in time, we can apply the Impact Theorem, which states that:

$m\cdot v_{o} +\Sigma F \cdot \Delta t = m\cdot v_{f}$ (2)