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3 years ago

Why are electromagnets, rather than permanent magnets, used in MRLs?

Physics

1 answer:

yKpoI14uk [10]3 years ago

5 0

Answer:

The main advantage of an electromagnet over a permanent magnet is that the magnetic field can be quickly changed by controlling the amount of electric current in the winding. However, unlike a permanent magnet that needs no power, an electromagnet requires a continuous supply of current to maintain the magnetic field.

Explanation:

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Which vector should be negative?

Bas_tet [7]

The velocity of a falling object. In physics, down is regarded as a negative direction.

5 0

3 years ago

It is not possible to convert work entirely into heat. It is impossible to transfer heat from a cooler to a hotter body. The sec

Irina-Kira [14]

Complete Question:

Which one of the following is a

true statement?

Group of answer choices.

A) The second law of thermodynamics is a consequence of the first law of thermodynamics.

B) It is possible for heat to flow spontaneously from a hot body to a cold one or from a cold one

to a hot one, depending on whether or not the process is reversible or irreversible.

C) It is not possible to convert work entirely into heat.

D) It is impossible to transfer heat from a cooler to a hotter body.

E) All of these statements are false.

Answer:

E) All of these statements are false.

Explanation:

All of the following statements are false;

I. The second law of thermodynamics is a consequence of the first law of thermodynamics. The second law of thermodynamics is about a physical quantity known as entropy while the first law of thermodynamics states that energy cannot be created or destroyed but can only be transformed from one form to another.

II. It is possible for heat to flow spontaneously from a hot body to a cold one or from a cold one

to a hot one, depending on whether or not the process is reversible or irreversible. According to the second law of thermodynamics this is false due to the entropy.

III. It is not possible to convert work entirely into heat. It is possible to completely convert work into heat because it involves transferring energy.

IV. It is impossible to transfer heat from a cooler to a hotter body.

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2 years ago

This chemical equation represents a ______________ reaction.

Ede4ka [16]

Answer:

you didnt put anything

Explanation:

7 0

3 years ago

Read 2 more answers

A spherical asteroid of average density would have a mass of 8.7×1013kg if its radius were 2.0 km.A)If you and your spacesuit ha

WITCHER [35]

A) 0.189 N

The weight of the person on the asteroid is equal to the gravitational force exerted by the asteroid on the person, at a location on the surface of the asteroid:

$F=\frac{GMm}{R^2}$

where

G is the gravitational constant

8.7×10^13 kg is the mass of the asteroid

m = 130 kg is the mass of the man

R = 2.0 km = 2000 m is the radius of the asteroid

Substituting into the equation, we find

$F=\frac{(6.67\cdot 10^{-11})(8.7\cdot 10^{13} kg)(130 kg)}{(2000 m)^2}0.189 N=$

B) 2.41 m/s

In order to orbit just above the surface of the asteroid (r=R), the centripetal force that keeps the astronaut in orbit must be equal to the gravitational force acting on the astronaut:

$\frac{GMm}{R^2}=\frac{mv^2}{R}$

where

v is the speed of the astronaut

Solving the formula for v, we find the minimum speed at which the astronaut should launch himself and then orbit the asteroid just above the surface:

$v=\sqrt{\frac{2GM}{R}}=\sqrt{\frac{2(6.67\cdot 10^{-11})(8.7\cdot 10^{13} kg)}{2000 m}}=2.41 m/s$

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3 years ago

Picture showing four cards in a row with labels 'First animal appears on land', 'First life form appears in the sea', 'First roc

sasho [114]

The answer would be 'First rocks formed on Earth'.

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3 years ago