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3 years ago

An electromagnet is a temporary magnet due to which of the following?

Physics

2 answers:

mixer [17]3 years ago

7 0

Answer:

The magnet is only present when a current is present.

Explanation:

As we know that in electromagnet there is a coil of certain resistance which is connected to a energy source which will provide constant potential difference to the coil

Due to constant potential difference the coil will have a current flow in it due to which there exist a magnetic field along the axis of the coil

this magnetic field is only possible when current is flowing in the coil

So it is given as

$B = \frac{\mu_0 N i}{L}$

here we know

N = number of turns

L = length of solenoid

i = current in it

So correct answer is

The magnet is only present when a current is present.

chubhunter [2.5K]3 years ago

5 0

I think the correct answer from the choices listed above is the first option. An electromagnet is a temporary magnet because the magnet is only present when a current is present. The magnetic field disappears when the current is turned off. Hope this answers the question. Have a nice day.

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The gravitational force experienced by Earth due to the Moon is ________ the gravitational force experienced by the Moon due to

Vsevolod [243]

The gravitational force experienced by Earth due to the Moon is equal to the gravitational force experienced by the Moon due to Earth.

Explanation:

The force that attracts any two objects/bodies with mass towards each other is defined as gravitational force. Generally the gravitational force is attractive, as it always pulls the masses together and never pushes them apart.

The gravitational force can be calculated effectively using the following formula: F=GMmr^2

where “G” is the gravitational constant.

Though gravity has the ability to pull the masses together, it is the weakest force in the nature.

The mass of the Earth and moon varies, but still the gravitational force felt by the Earth and Moon are alike.

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3 years ago

If velocity is positive, which woul

shusha [124]

Answer:

C. An inital volocity that is faster than the final volocity

Explanation:

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3 years ago

A baseball player hits a homerun, and the ball lands in the left field seats, which is 103m away from the point at which the bal

Sati [7]

(a) The ball has a final velocity vector

$\mathbf v_f=v_{x,f}\,\mathbf i+v_{y,f}\,\mathbf j$

with horizontal and vertical components, respectively,

$v_{x,f}=\left(20.5\dfrac{\rm m}{\rm s}\right)\cos(-38^\circ)\approx16.2\dfrac{\rm m}{\rm s}$

$v_{y,f}=\left(20.5\dfrac{\rm m}{\rm s}\right)\sin(-38^\circ)\approx-12.6\dfrac{\rm m}{\rm s}$

The horizontal component of the ball's velocity is constant throughout its trajectory, so $v_{x,i}=v_{x,f}$ , and the horizontal distance x that it covers after time t is

$x=v_{x,i}t=v_{x,f}t$

It lands 103 m away from where it's hit, so we can determine the time it it spends in the air:

$103\,\mathrm m=\left(16.2\dfrac{\rm m}{\rm s}\right)t\implies t\approx6.38\,\mathrm s$

The vertical component of the ball's velocity at time t is

$v_{y,f}=v_{y,i}-gt$

where g = 9.80 m/s² is the magnitude of the acceleration due to gravity. Solve for the vertical component of the initial velocity:

$-12.6\dfrac{\rm m}{\rm s}=v_{y,i}-\left(9.80\dfrac{\rm m}{\mathrm s^2}\right)(6.38\,\mathrm s)\implies v_{y,i}\approx49.9\dfrac{\rm m}{\rm s}$

So, the initial velocity vector is

$\mathbf v_i=v_{x,i}\,\mathbf i+v_{y,i}\,\mathbf j=\left(16.2\dfrac{\rm m}{\rm s}\right)\,\mathbf i+\left(49.9\dfrac{\rm m}{\rm s}\right)\,\mathbf j$

which carries an initial speed of

$\|\mathbf v_i\|=\sqrt{{v_{x,i}}^2+{v_{y,i}}^2}\approx\boxed{52.4\dfrac{\rm m}{\rm s}}$

and direction θ such that

$\tan\theta=\dfrac{v_{y,i}}{v_{x,i}}\implies\theta\approx\boxed{72.0^\circ}$

(b) I assume you're supposed to find the height of the ball when it lands in the seats. The ball's height y at time t is

$y=v_{y,i}t-\dfrac12gt^2$

so that when it lands in the seats at t ≈ 6.38 s, it has a height of

$y=\left(49.9\dfrac{\rm m}{\rm s}\right)(6.38\,\mathrm s)-\dfrac12\left(9.80\dfrac{\rm m}{\mathrm s^2}\right)(6.38\,\mathrm s)^2\approx\boxed{119\,\mathrm m}$

6 0

3 years ago

How do forces affect the motion of an object?

cricket20 [7]

Explanation:

Unbalanced Forces in Action

Unbalanced forces can change the motion of an object in two ways. ... Second, when unbalanced forces act on a moving object, the velocity of the object will change. Remember that a change in velocity means a change in speed, direction or both speed and direction.

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3 years ago

What is the final temperature when 50 g of water at 20°c is mixed with 75 g of water at 60°c

tatyana61 [14]

44C i think. Do you have options for the answer?

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3 years ago